1368 lines
34 KiB
C++
Executable File
1368 lines
34 KiB
C++
Executable File
// file layer on top of POSIX.
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// provides streaming support and caching.
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//
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// Copyright (c) 2004 Jan Wassenberg
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//
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// This file is free software; you can redistribute it and/or
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// modify it under the terms of the GNU General Public License as
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// published by the Free Software Foundation; either version 2 of the
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// License, or (at your option) any later version.
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//
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// This file is distributed in the hope that it will be useful, but
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// WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// General Public License for more details.
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//
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// Contact info:
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// Jan.Wassenberg@stud.uni-karlsruhe.de
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// http://www.stud.uni-karlsruhe.de/~urkt/
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#include "precompiled.h"
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#include "lib.h"
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#include "file.h"
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#include "h_mgr.h"
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#include "mem.h"
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#include "detect.h"
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#include "adts.h"
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// block := power-of-two sized chunk of a file.
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// all transfers are expanded to naturally aligned, whole blocks
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// (this makes caching parts of files feasible; it is also much faster
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// for some aio implementations, e.g. wposix).
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const size_t BLOCK_SIZE_LOG2 = 16; // 2**16 = 64 KB
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const size_t BLOCK_SIZE = 1ul << BLOCK_SIZE_LOG2;
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// rationale for aio, instead of only using mmap:
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// - parallel: instead of just waiting for the transfer to complete,
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// other work can be done in the meantime.
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// example: decompressing from a Zip archive is practically free,
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// because we inflate one block while reading the next.
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// - throughput: with aio, the drive always has something to do, as opposed
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// to read requests triggered by the OS for mapped files, which come
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// in smaller chunks. this leads to much higher transfer rates.
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// - memory: when used with VFS, aio makes better use of a file cache.
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// data is generally compressed in an archive. a cache should store the
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// decompressed and decoded (e.g. TGA color swapping) data; mmap would
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// keep the original, compressed data in memory, which doesn't help.
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// we bypass the OS file cache via aio, and store partial blocks here (*);
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// higher level routines will cache the actual useful data.
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// * requests for part of a block are usually followed by another.
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// return the native equivalent of the given portable path
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// (i.e. convert all '/' to the platform's directory separator)
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// makes sure length < PATH_MAX.
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static int mk_native_path(const char* const path, char* const n_path)
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{
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/*
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// if there's a platform with multiple-character DIR_SEP,
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// scan through the path and add space for each separator found.
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const size_t len = strlen(p_path);
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n_path = (const char*)malloc(len * sizeof(char));
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if(!n_path)
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return ERR_NO_MEM;
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*/
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const char* portable = path;
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char* native = (char*)n_path;
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size_t len = 0;
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for(;;)
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{
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len++;
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if(len >= PATH_MAX)
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return -1;
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char c = *portable++;
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if(c == '/')
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c = DIR_SEP;
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*native++ = c;
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if(c == '\0')
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break;
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}
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return 0;
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}
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// set current directory to rel_path, relative to the path to the executable,
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// which is taken from argv0.
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//
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// example: executable in "$install_dir/system"; desired root dir is
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// "$install_dir/data" => rel_path = "../data".
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//
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// this is necessary because the current directory is unknown at startup
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// (e.g. it isn't set when invoked via batch file), and this is the
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// easiest portable way to find our install directory.
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//
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// can only be called once, by design (see below). rel_path is trusted.
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int file_rel_chdir(const char* argv0, const char* const rel_path)
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{
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const char* msg = 0;
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// security check: only allow attempting to chdir once, so that malicious
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// code cannot circumvent the VFS checks that disallow access to anything
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// above the current directory (set here).
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// this routine is called early at startup, so any subsequent attempts
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// are likely bogus.
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static bool already_attempted;
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if(already_attempted)
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{
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msg = "called more than once";
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goto fail;
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}
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already_attempted = true;
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{
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// Win32-specific: if started via batch file, argv0 might not end
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// with ".exe". access and realpath require the filename with extension,
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// so append it if not there. we don't get the full path either in that
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// case, but realpath takes care of it.
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#ifdef _WIN32
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char fixed_argv0[PATH_MAX];
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if(!strchr(argv0, '.'))
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{
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strncpy(fixed_argv0, argv0, PATH_MAX-5);
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strcat(fixed_argv0, ".exe");
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argv0 = fixed_argv0;
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}
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#endif
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// get full path to executable
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if(access(argv0, X_OK) < 0)
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goto fail;
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char n_path[PATH_MAX+1];
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n_path[PATH_MAX] = '\0';
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if(!realpath(argv0, n_path))
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goto fail;
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const size_t n_path_len = strlen(n_path);
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// strip executable name and append rel_path
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char* fn = strrchr(n_path, DIR_SEP);
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if(!fn)
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{
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msg = "realpath returned an invalid path?";
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goto fail;
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}
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char* pos = fn+1; // will overwrite executable name
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CHECK_ERR(mk_native_path(rel_path, pos));
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if(chdir(n_path) < 0)
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goto fail;
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return 0;
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}
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fail:
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debug_warn("file_rel_chdir failed");
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if(msg)
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{
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debug_out("file_rel_chdir: %s\n", msg);
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printf("%s\n", msg);
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return -1;
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}
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return -errno;
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}
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// need to store entries returned by readdir so they can be sorted.
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struct DirEnt
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{
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const std::string name;
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const uint flags;
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const off_t size;
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DirEnt(const char* const _name, const uint _flags, const off_t _size)
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: name(_name), flags(_flags), size(_size) {}
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};
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// pointer to DirEnt: faster sorting, but more allocs.
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typedef std::vector<const DirEnt*> DirEnts;
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typedef DirEnts::const_iterator DirEntIt;
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static bool dirent_less(const DirEnt* const d1, const DirEnt* const d2)
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{ return d1->name.compare(d2->name) < 0; }
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// we give the callback the directory-entry-name only - not the
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// absolute path, nor <dir> prepended. rationale: some users don't need it,
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// and would need to strip it. there are not enough users requiring it to
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// justify that. this routine does actually generate the absolute path
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// for use with stat, but in native form - can't use that.
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int file_enum(const char* const dir, const FileCB cb, const uintptr_t user)
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{
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char n_path[PATH_MAX+1];
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n_path[PATH_MAX] = '\0';
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// will append filename to this, hence "path".
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// 0-terminate simplifies filename strncpy below.
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CHECK_ERR(mk_native_path(dir, n_path));
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// all entries are enumerated (adding to this container),
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// std::sort-ed, then all passed to cb.
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DirEnts dirents;
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int stat_err = 0;
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int cb_err = 0;
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int ret;
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DIR* const os_dir = opendir(n_path);
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if(!os_dir)
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return -1;
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// will append file names here
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const size_t n_path_len = strlen(n_path);
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char* fn_start = n_path + n_path_len;
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*fn_start++ = DIR_SEP;
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struct dirent* os_ent;
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while((os_ent = readdir(os_dir)))
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{
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const char* fn = os_ent->d_name;
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strncpy(fn_start, fn, PATH_MAX-n_path_len);
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// stat needs the full path. this is easier than changing
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// directory every time, and should be fast enough.
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// BTW, direct strcpy is faster than path_append -
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// we save a strlen every iteration.
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// no need to go through file_stat -
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// we already have the native path.
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struct stat s;
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ret = stat(n_path, &s);
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if(ret < 0)
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{
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if(stat_err == 0)
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stat_err = ret;
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continue;
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}
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uint flags = 0;
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off_t size = s.st_size;
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// dir
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if(s.st_mode & S_IFDIR)
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{
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// skip . and ..
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if(fn[0] == '.' && (fn[1] == '\0' || (fn[1] == '.' && fn[2] == '\0')))
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continue;
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flags |= LOC_DIR;
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size = -1;
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}
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// skip if neither dir nor file
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else if(!(s.st_mode & S_IFREG))
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continue;
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const DirEnt* const ent = new DirEnt(fn, flags, size);
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dirents.push_back(ent);
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}
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closedir(os_dir);
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std::sort(dirents.begin(), dirents.end(), dirent_less);
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DirEntIt it;
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for(it = dirents.begin(); it != dirents.end(); ++it)
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{
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const DirEnt* const ent = *it;
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const char* name_c = ent->name.c_str();
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const uint flags = ent->flags;
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const ssize_t size = ent->size;
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ret = cb(name_c, flags, size, user);
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if(ret < 0)
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if(cb_err == 0)
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cb_err = ret;
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}
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for(it = dirents.begin(); it != dirents.end(); ++it)
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delete *it;
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if(cb_err < 0)
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return cb_err;
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return stat_err;
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}
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int file_stat(const char* const path, struct stat* const s)
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{
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char n_path[PATH_MAX+1];
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CHECK_ERR(mk_native_path(path, n_path));
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return stat(n_path, s);
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}
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///////////////////////////////////////////////////////////////////////////////
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//
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// file open/close
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// stores information about file (e.g. size) in File struct
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//
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///////////////////////////////////////////////////////////////////////////////
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// interface rationale:
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// - this module depends on the handle manager for IO management,
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// but should be useable without the VFS (even if they are designed
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// to work together).
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// - allocating a Handle for the file info would solve several problems
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// (see below), but we don't want to allocate 2..3 (VFS, file, Zip file)
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// for every file opened - that'd add up quickly.
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// the Files are always freed at exit though, since they're part of
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// VFile handles in the VFS.
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// - we want the VFS open logic to be triggered on file invalidate
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// (if the dev. file is deleted, we should use what's in the archives).
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// we don't want to make this module depend on VFS, so we can't
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// call up into vfs_foreach_path from reload here =>
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// VFS needs to allocate the handle.
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// - no problem exposing our internals via File struct -
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// we're only used by the VFS and Zip modules. don't bother making
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// an opaque struct - that'd have to be kept in sync with the real thing.
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// - when Zip opens its archives via file_open, a handle isn't needed -
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// the Zip module hides its File struct (required to close the file),
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// and the Handle approach doesn't guard against some idiot calling
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// close(our_fd) directly, either.
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// marker for File struct, to make sure it's valid
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#ifdef PARANOIA
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static const u32 FILE_MAGIC = FOURCC('F','I','L','E');
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#endif
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static int file_validate(const uint line, File* const f)
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{
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const char* msg = "";
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int err = -1;
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if(!f)
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{
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msg = "File* parameter = 0";
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err = ERR_INVALID_PARAM;
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}
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#ifdef PARANOIA
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else if(f->magic != FILE_MAGIC)
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msg = "File corrupted (magic field incorrect)";
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#endif
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else if(f->fd < 0)
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msg = "File fd invalid (< 0)";
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else if((f->mapping != 0) ^ (f->map_refs != 0))
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msg = "File mapping without refs";
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#ifndef NDEBUG
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else if(!f->fn_hash)
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msg = "File fn_hash not set";
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#endif
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// everything is OK
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else
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return 0;
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// failed somewhere - err is the error code,
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// or -1 if not set specifically above.
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debug_out("file_validate at line %d failed: %s\n", line, msg);
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debug_warn("file_validate failed");
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return err;
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}
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#define CHECK_FILE(f)\
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do\
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{\
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int err = file_validate(__LINE__, f);\
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if(err < 0)\
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return err;\
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}\
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while(0);
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int file_open(const char* const p_fn, const uint flags, File* const f)
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{
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memset(f, 0, sizeof(File));
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char n_fn[PATH_MAX];
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CHECK_ERR(mk_native_path(p_fn, n_fn));
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if(!f)
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goto invalid_f;
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// jump to CHECK_FILE post-check, which will handle this.
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{
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// don't stat if opening for writing - the file may not exist yet
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off_t size = 0;
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int mode = O_RDONLY;
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if(flags & FILE_WRITE)
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mode = O_WRONLY;
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else
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{
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struct stat s;
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if(stat(n_fn, &s) < 0)
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return -1;
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if(!(s.st_mode & S_IFREG))
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return -1;
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size = s.st_size;
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}
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int fd = open(n_fn, mode);
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if(fd < 0)
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return -1;
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#ifdef PARANOIA
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f->magic = FILE_MAGIC;
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#endif
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f->flags = flags;
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f->size = size;
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f->fn_hash = fnv_hash(n_fn); // copy filename instead?
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f->mapping = 0;
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f->map_refs = 0;
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f->fd = fd;
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}
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invalid_f:
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CHECK_FILE(f);
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return 0;
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}
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int file_close(File* const f)
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{
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CHECK_FILE(f);
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// make sure the mapping is actually freed,
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// regardless of how many references remain.
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if(f->map_refs > 1)
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f->map_refs = 1;
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file_unmap(f);
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|
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// (check fd to avoid BoundsChecker warning about invalid close() param)
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if(f->fd != -1)
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{
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close(f->fd);
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f->fd = -1;
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}
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f->size = 0;
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return 0;
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}
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|
|
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///////////////////////////////////////////////////////////////////////////////
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//
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// low level IO
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// thin wrapper over aio; no alignment or caching
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//
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///////////////////////////////////////////////////////////////////////////////
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|
|
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struct ll_cb
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{
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aiocb cb;
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};
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|
|
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int ll_start_io(File* const f, const off_t ofs, size_t size, void* const p, ll_cb* const lcb)
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{
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CHECK_FILE(f);
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|
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if(size == 0)
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{
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debug_warn("ll_start_io: size = 0 - why?");
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return ERR_INVALID_PARAM;
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}
|
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|
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const int op = (f->flags & FILE_WRITE)? LIO_WRITE : LIO_READ;
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|
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// cut off at EOF.
|
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// avoid min() due to type conversion warnings.
|
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const off_t bytes_left = f->size - ofs;
|
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if(bytes_left < 0)
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return ERR_EOF;
|
|
if((off_t)size > bytes_left)
|
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size = (size_t)bytes_left;
|
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// guaranteed to fit, since size was > bytes_left
|
|
|
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aiocb* cb = &lcb->cb;
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|
|
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// send off async read/write request
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cb->aio_lio_opcode = op;
|
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cb->aio_buf = p;
|
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cb->aio_fildes = f->fd;
|
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cb->aio_offset = (off_t)ofs;
|
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cb->aio_nbytes = (size_t)size;
|
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return lio_listio(LIO_NOWAIT, &cb, 1, (struct sigevent*)0);
|
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// this just issues the I/O - doesn't wait until complete.
|
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}
|
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|
|
|
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// as a convenience, return a pointer to the transfer buffer
|
|
// (rather than expose the ll_cb internals)
|
|
ssize_t ll_wait_io(ll_cb* const lcb, void*& p)
|
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{
|
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aiocb* cb = &lcb->cb;
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|
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// wait for transfer to complete.
|
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while(aio_error(cb) == EINPROGRESS)
|
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aio_suspend(&cb, 1, NULL);
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|
|
// posix has aio_buf as volatile void, and gcc doesn't like to cast it
|
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// implicitly
|
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p = (void *)cb->aio_buf;
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|
|
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// return how much was actually transferred,
|
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// or -1 if the transfer failed.
|
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return aio_return(cb);
|
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}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// block cache
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
static Cache<void*> c;
|
|
// don't need a Block struct as cache data -
|
|
// it stores its associated ID, and does refcounting
|
|
// with lock().
|
|
|
|
|
|
// create an id for use with the Cache that uniquely identifies
|
|
// the block from the file <fn_hash> containing <ofs>.
|
|
static u64 block_make_id(const u32 fn_hash, const off_t ofs)
|
|
{
|
|
// id format: filename hash | block number
|
|
// 63 32 31 0
|
|
//
|
|
// we assume the hash (currently: FNV) is unique for all filenames.
|
|
// chance of a collision is tiny, and a build tool will ensure
|
|
// filenames in the VFS archives are safe.
|
|
//
|
|
// block_num will always fit in 32 bits (assuming maximum file size
|
|
// = 2^32 * BLOCK_SIZE = 2^48 -- plenty); we check this, but don't
|
|
// include a workaround. we could return 0, and the caller would have
|
|
// to allocate their own buffer, but don't bother.
|
|
|
|
// make sure block_num fits in 32 bits
|
|
const size_t block_num = ofs / BLOCK_SIZE;
|
|
assert(block_num <= 0xffffffff);
|
|
|
|
u64 id = fn_hash; // careful, don't shift a u32 32 bits left
|
|
id <<= 32;
|
|
id |= block_num;
|
|
return id;
|
|
}
|
|
|
|
|
|
//
|
|
static void* block_alloc(const u64 id)
|
|
{
|
|
// initialize cache, if not done already.
|
|
static bool cache_initialized;
|
|
if(!cache_initialized)
|
|
{
|
|
get_mem_status();
|
|
// TODO: calculate size
|
|
const size_t num_blocks = 16;
|
|
|
|
// evil: waste some mem (up to one block) to make sure the first block
|
|
// isn't at the start of the allocation, so that users can't
|
|
// mem_free() it. do this by manually aligning the pool.
|
|
//
|
|
// allocator will free the whole thing at exit.
|
|
void* const pool = mem_alloc((num_blocks+1) * BLOCK_SIZE);
|
|
if(!pool)
|
|
return 0;
|
|
|
|
const uintptr_t start = round_up((uintptr_t)pool + 1, BLOCK_SIZE);
|
|
// +1 => if already block-aligned, add a whole block!
|
|
|
|
// add all blocks to cache
|
|
void* p = (void*)start;
|
|
for(size_t i = 0; i < num_blocks; i++)
|
|
{
|
|
if(c.grow(p) < 0)
|
|
debug_warn("block_alloc: Cache::grow failed!");
|
|
// currently can't fail.
|
|
p = (char*)p + BLOCK_SIZE;
|
|
}
|
|
|
|
cache_initialized = true;
|
|
}
|
|
|
|
void** const entry = c.assign(id);
|
|
if(!entry)
|
|
return 0;
|
|
void* const block = *entry;
|
|
|
|
if(c.lock(id, true) < 0)
|
|
debug_warn("block_alloc: Cache::lock failed!");
|
|
// can't happen: only cause is tag not found, but we successfully
|
|
// added it above. if it did fail, that'd be bad: we leak the block,
|
|
// and/or the buffer may be displaced while in use. hence, assert.
|
|
|
|
return block;
|
|
}
|
|
|
|
|
|
// modifying cached blocks is not supported.
|
|
// we could allocate a new buffer and update the cache to point to that,
|
|
// but that'd fragment our memory pool.
|
|
// instead, add a copy on write call, if necessary.
|
|
|
|
|
|
static int block_retrieve(const u64 id, void*& p)
|
|
{
|
|
void** const entry = c.retrieve(id);
|
|
if(entry)
|
|
{
|
|
p = *entry;
|
|
c.lock(id, true); // add reference
|
|
return 0;
|
|
}
|
|
else
|
|
{
|
|
p = 0;
|
|
return -1;
|
|
}
|
|
|
|
// important note:
|
|
// for the purposes of starting the IO, we can regard blocks whose read
|
|
// is still pending it as cached. when getting the IO results,
|
|
// we'll have to wait on the actual IO for that block.
|
|
//
|
|
// don't want to require IOs to be completed in order of issue:
|
|
// that'd mean only 1 caller can read from file at a time.
|
|
// would obviate associating id with IO, but is overly restrictive.
|
|
}
|
|
|
|
|
|
static int block_discard(const u64 id)
|
|
{
|
|
return c.lock(id, false);
|
|
}
|
|
|
|
|
|
int file_free_buf(void*& p)
|
|
{
|
|
const uintptr_t _p = (uintptr_t)p;
|
|
void* const actual_p = (void*)(_p - (_p % BLOCK_SIZE)); // round down
|
|
|
|
return mem_free(actual_p);
|
|
|
|
// remove from cache?
|
|
|
|
// check if in use?
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// async I/O
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
struct IO
|
|
{
|
|
u64 block_id;
|
|
// transferring via cache (=> BLOCK_SIZE aligned) iff != 0
|
|
|
|
void* block;
|
|
// valid because cache line is locked
|
|
// (rug can't be pulled out from under us)
|
|
|
|
ll_cb* cb;
|
|
// this is too big to store here. IOs are reused,
|
|
// so we don't allocate a new cb every file_start_io.
|
|
|
|
void* user_p;
|
|
off_t user_ofs;
|
|
size_t user_size;
|
|
|
|
int cached : 1;
|
|
int pending : 1;
|
|
};
|
|
|
|
H_TYPE_DEFINE(IO)
|
|
|
|
|
|
// don't support forcibly closing files => don't need to keep track of
|
|
// all IOs pending for each file. too much work, little benefit.
|
|
|
|
|
|
static void IO_init(IO* io, va_list args)
|
|
{
|
|
const size_t cb_size = round_up(sizeof(struct ll_cb), 16);
|
|
io->cb = (ll_cb*)mem_alloc(cb_size, 16, MEM_ZERO);
|
|
}
|
|
|
|
static void IO_dtor(IO* io)
|
|
{
|
|
mem_free(io->cb);
|
|
}
|
|
|
|
|
|
// TODO: prevent reload if already open, i.e. IO pending
|
|
|
|
// we don't support transparent read resume after file invalidation.
|
|
// if the file has changed, we'd risk returning inconsistent data.
|
|
// i don't think it's possible anyway, without controlling the AIO
|
|
// implementation: when we cancel, we can't prevent the app from calling
|
|
// aio_result, which would terminate the read.
|
|
static int IO_reload(IO* io, const char* fn)
|
|
{
|
|
return io->cb? 0 : ERR_NO_MEM;
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
// extra layer on top of h_alloc, so we can reuse IOs
|
|
//
|
|
// (avoids allocating the cb every IO => less heap fragmentation)
|
|
//
|
|
// don't worry about reassigning IOs to their associated file -
|
|
// they don't need to be reloaded, since the VFS refuses reload
|
|
// requests for files with pending IO.
|
|
|
|
typedef std::vector<Handle> IOList;
|
|
|
|
// accessed MRU for better cache locality
|
|
static IOList free_ios;
|
|
|
|
// list of all IOs allocated.
|
|
// used to find active IO, given id (see below).
|
|
// also used to free all IOs before the handle manager
|
|
// cleans up at exit, so they aren't seen as resource leaks.
|
|
|
|
static IOList all_ios;
|
|
|
|
struct Free
|
|
{
|
|
void operator()(Handle h)
|
|
{
|
|
h_free(h, H_IO);
|
|
}
|
|
};
|
|
|
|
// free all allocated IOs, so they aren't seen as resource leaks.
|
|
static void io_shutdown(void)
|
|
{
|
|
std::for_each(all_ios.begin(), all_ios.end(), Free());
|
|
}
|
|
|
|
|
|
static Handle io_alloc()
|
|
{
|
|
ONCE(atexit(io_shutdown));
|
|
/*
|
|
// grab from freelist
|
|
if(!free_ios.empty())
|
|
{
|
|
Handle h = free_ios.back();
|
|
free_ios.pop_back();
|
|
|
|
// note:
|
|
// we don't check if the freelist contains valid handles.
|
|
// that "can't happen", and if it does, it'll be caught
|
|
// by the handle dereference in file_start_io.
|
|
//
|
|
// no one else can actually free an IO - that would require
|
|
// its handle type, which is private to this module.
|
|
// the free_io call just adds it to the freelist;
|
|
// all allocated IOs are destroyed in io_cleanup at exit.
|
|
|
|
return h;
|
|
}
|
|
*/
|
|
// allocate a new IO
|
|
Handle h = h_alloc(H_IO, 0);
|
|
// .. it's valid - store in list.
|
|
if(h > 0)
|
|
all_ios.push_back(h);
|
|
return h;
|
|
}
|
|
|
|
|
|
static int io_free(const Handle hio)
|
|
{
|
|
H_DEREF(hio, IO, io);
|
|
|
|
if(io->pending)
|
|
{
|
|
debug_warn("io_free: IO pending");
|
|
return -1;
|
|
}
|
|
|
|
// clear the other IO fields, just to be sure.
|
|
// (but don't memset the whole thing - that'd trash the cb pointer!)
|
|
io->block_id = 0;
|
|
io->block = 0;
|
|
io->cached = 0;
|
|
io->user_ofs = 0;
|
|
io->user_size = 0;
|
|
io->user_p = 0;
|
|
memset(io->cb, 0, sizeof(ll_cb));
|
|
|
|
// TODO: complain if buffer not yet freed?
|
|
|
|
// we know hio is valid, since we successfully dereferenced above.
|
|
free_ios.push_back(hio);
|
|
return 0;
|
|
}
|
|
|
|
|
|
// need to find IO, given id, to make sure a block
|
|
// that is marked cached has actually been read.
|
|
// it is expected that there only be a few allocated IOs,
|
|
// so it's ok to search this list every cache hit.
|
|
// adding to the cache data structure would be messier.
|
|
|
|
struct FindBlock : public std::binary_function<Handle, u64, bool>
|
|
{
|
|
bool operator()(const Handle hio, const u64 block_id) const
|
|
{
|
|
// can't use H_DEREF - we return bool
|
|
IO* io = (IO*)h_user_data(hio, H_IO);
|
|
if(!io)
|
|
{
|
|
debug_warn("invalid handle in all_ios list!");
|
|
return false;
|
|
}
|
|
return io->block_id == block_id;
|
|
}
|
|
};
|
|
|
|
static Handle io_find(const u64 block_id)
|
|
{
|
|
IOList::const_iterator it;
|
|
it = std::find_if(all_ios.begin(), all_ios.end(), std::bind2nd(FindBlock(), block_id));
|
|
// not found
|
|
if(it == all_ios.end())
|
|
return 0;
|
|
|
|
return *it;
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
|
|
// rationale for extra alignment / copy layer, even though aio takes care of it:
|
|
// aio would pad to its minimum read alignment, copy over, and be done;
|
|
// in our case, if something is unaligned, a request for the remainder of the
|
|
// block is likely to follow, so we want to cache the whole block.
|
|
|
|
|
|
// pads the request up to BLOCK_SIZE, and stores the original parameters in IO.
|
|
// transfers of more than 1 block (including padding) are allowed, but do not
|
|
// go through the cache. don't see any case where that's necessary, though.
|
|
Handle file_start_io(File* const f, const off_t user_ofs, size_t user_size, void* const user_p)
|
|
{
|
|
int err;
|
|
|
|
CHECK_FILE(f);
|
|
|
|
if(user_size == 0)
|
|
{
|
|
debug_warn("file_start_io: user_size = 0 - why?");
|
|
return ERR_INVALID_PARAM;
|
|
}
|
|
|
|
const int op = (f->flags & FILE_WRITE)? LIO_WRITE : LIO_READ;
|
|
|
|
// cut off at EOF.
|
|
// avoid min() due to type conversion warnings.
|
|
const off_t bytes_left = f->size - user_ofs;
|
|
if(bytes_left < 0)
|
|
return ERR_EOF;
|
|
if((off_t)user_size > bytes_left)
|
|
user_size = (size_t)bytes_left;
|
|
// guaranteed to fit, since size was > bytes_left
|
|
|
|
u64 block_id = block_make_id(f->fn_hash, user_ofs);
|
|
// reset to 0 if transferring more than 1 block.
|
|
|
|
// allocate IO slot
|
|
Handle hio = io_alloc();
|
|
H_DEREF(hio, IO, io);
|
|
io->block_id = block_id;
|
|
io->user_p = user_p;
|
|
io->user_ofs = user_ofs;
|
|
io->user_size = user_size;
|
|
// notes: io->cached, io->pending and io->block are already zeroed;
|
|
// cb will receive the actual IO request (aligned offset and size).
|
|
|
|
#ifdef PARANOIA
|
|
debug_out("file_start_io hio=%I64x ofs=%d size=%d\n", hio, user_ofs, user_size);
|
|
#endif
|
|
|
|
// aio already safely handles unaligned buffers or offsets.
|
|
// when reading zip files, we don't want to repeat a read
|
|
// if a block contains the end of one file and start of the next
|
|
// (speed concern).
|
|
// therefore, we align and round up to whole blocks.
|
|
//
|
|
// note: cache even if this is the last block before EOF:
|
|
// a zip archive may contain one last file in the block.
|
|
// if not, no loss - the buffer will be LRU, and reused.
|
|
|
|
off_t ofs = user_ofs;
|
|
const size_t padding = ofs % BLOCK_SIZE;
|
|
ofs -= (off_t)padding;
|
|
const size_t size = round_up(padding + user_size, BLOCK_SIZE);
|
|
|
|
|
|
|
|
// if already cached, we're done
|
|
if(size == BLOCK_SIZE && block_retrieve(block_id, io->block) == 0)
|
|
{
|
|
#ifdef PARANOIA
|
|
debug_out("file_start_io: cached! block # = %d\n", block_id & 0xffffffff);
|
|
#endif
|
|
io->cached = 1;
|
|
return hio;
|
|
}
|
|
|
|
|
|
void* buf = 0;
|
|
void* our_buf = 0;
|
|
|
|
if(user_p && !padding)
|
|
buf = user_p;
|
|
else
|
|
{
|
|
if(size == BLOCK_SIZE)
|
|
our_buf = io->block = block_alloc(block_id);
|
|
// transferring more than one block - doesn't go through cache!
|
|
else
|
|
{
|
|
our_buf = mem_alloc(size, BLOCK_SIZE);
|
|
block_id = 0;
|
|
}
|
|
if(!our_buf)
|
|
{
|
|
err = ERR_NO_MEM;
|
|
goto fail;
|
|
}
|
|
|
|
buf = our_buf;
|
|
}
|
|
|
|
err = ll_start_io(f, ofs, size, buf, io->cb);
|
|
|
|
if(err < 0)
|
|
{
|
|
fail:
|
|
file_discard_io(hio);
|
|
if(size != BLOCK_SIZE)
|
|
file_free_buf(our_buf);
|
|
return err;
|
|
}
|
|
|
|
return hio;
|
|
}
|
|
|
|
|
|
int file_wait_io(const Handle hio, void*& p, size_t& size)
|
|
{
|
|
#ifdef PARANOIA
|
|
debug_out("file_wait_io: hio=%I64x\n", hio);
|
|
#endif
|
|
|
|
int ret = 0;
|
|
|
|
p = 0;
|
|
size = 0;
|
|
|
|
H_DEREF(hio, IO, io);
|
|
ll_cb* cb = io->cb;
|
|
|
|
size = io->user_size;
|
|
|
|
void* transfer_buf;
|
|
ssize_t bytes_transferred;
|
|
|
|
// block's tag is in cache. need to check if its read is still pending.
|
|
if(io->cached)
|
|
{
|
|
Handle cache_hio = io_find(io->block_id);
|
|
// was already finished - don't wait
|
|
if(cache_hio <= 0)
|
|
goto skip_wait;
|
|
|
|
// not finished yet; will wait for it below, as with uncached reads.
|
|
H_DEREF(cache_hio, IO, cache_io);
|
|
// can't fail, since io_find has to dereference each handle.
|
|
cb = cache_io->cb;
|
|
}
|
|
|
|
bytes_transferred = ll_wait_io(cb, transfer_buf);
|
|
|
|
skip_wait:
|
|
|
|
if(io->block)
|
|
{
|
|
size_t padding = io->user_ofs % BLOCK_SIZE;
|
|
void* src = (char*)io->block + padding;
|
|
|
|
// copy over into user's buffer
|
|
if(io->user_p)
|
|
{
|
|
p = io->user_p;
|
|
memcpy(p, src, io->user_size);
|
|
}
|
|
// return pointer to cache block
|
|
else
|
|
p = src;
|
|
}
|
|
// we had read directly into target buffer
|
|
else
|
|
p = transfer_buf;
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
int file_discard_io(Handle& hio)
|
|
{
|
|
H_DEREF(hio, IO, io);
|
|
block_discard(io->block_id);
|
|
io_free(hio);
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
|
|
// transfer modes:
|
|
// *p != 0: *p is the source/destination address for the transfer.
|
|
// (FILE_MEM_READONLY?)
|
|
// *p == 0: allocate a buffer, read into it, and return it in *p.
|
|
// when no longer needed, it must be freed via file_free_buf.
|
|
// p == 0: read raw_size bytes from file, starting at offset raw_ofs,
|
|
// into temp buffers; each block read is passed to cb, which is
|
|
// expected to write actual_size bytes total to its output buffer
|
|
// (for which it is responsible).
|
|
// useful for reading compressed data.
|
|
//
|
|
// return (positive) number of raw bytes transferred if successful;
|
|
// otherwise, an error code.
|
|
ssize_t file_io(File* const f, const off_t raw_ofs, size_t raw_size, void** const p,
|
|
const FILE_IO_CB cb, const uintptr_t ctx) // optional
|
|
{
|
|
#ifdef PARANOIA
|
|
debug_out("file_io fd=%d size=%d ofs=%d\n", f->fd, raw_size, raw_ofs);
|
|
#endif
|
|
|
|
CHECK_FILE(f);
|
|
|
|
const bool is_write = (f->flags == FILE_WRITE);
|
|
|
|
//
|
|
// transfer parameters
|
|
//
|
|
|
|
// reading: make sure we don't go beyond EOF
|
|
if(!is_write)
|
|
{
|
|
// cut off at EOF.
|
|
// avoid min() due to type conversion warnings.
|
|
off_t bytes_left = f->size - raw_ofs;
|
|
if(bytes_left < 0)
|
|
return ERR_EOF;
|
|
if((off_t)raw_size > bytes_left)
|
|
raw_size = (size_t)bytes_left;
|
|
// guaranteed to fit, since size was > bytes_left
|
|
}
|
|
// writing: make sure buffer is valid
|
|
else
|
|
{
|
|
// temp buffer OR supposed to be allocated here: invalid
|
|
if(!p || !*p)
|
|
{
|
|
debug_warn("file_io: write to file from 0 buffer");
|
|
return ERR_INVALID_PARAM;
|
|
}
|
|
}
|
|
|
|
const size_t misalign = raw_ofs % BLOCK_SIZE;
|
|
|
|
// actual transfer start offset
|
|
// not aligned! aio takes care of initial unalignment;
|
|
// next read will be aligned, because we read up to the next block.
|
|
const off_t start_ofs = raw_ofs;
|
|
|
|
|
|
void* buf = 0; // I/O source or sink; assume temp buffer
|
|
void* our_buf = 0; // buffer we allocate, if necessary
|
|
|
|
// check buffer param
|
|
// .. temp buffer requested
|
|
if(!p)
|
|
; // nothing to do - buf already initialized to 0
|
|
// .. user specified, or requesting we allocate the buffer
|
|
else
|
|
{
|
|
// the underlying aio implementation likes buffer and offset to be
|
|
// sector-aligned; if not, the transfer goes through an align buffer,
|
|
// and requires an extra memcpy.
|
|
//
|
|
// if the user specifies an unaligned buffer, there's not much we can
|
|
// do - we can't assume the buffer contains padding. therefore,
|
|
// callers should let us allocate the buffer if possible.
|
|
//
|
|
// if ofs misalign = buffer, only the first and last blocks will need
|
|
// to be copied by aio, since we read up to the next block boundary.
|
|
// otherwise, everything will have to be copied; at least we split
|
|
// the read into blocks, so aio's buffer won't have to cover the
|
|
// whole file.
|
|
|
|
// user specified buffer
|
|
if(*p)
|
|
{
|
|
buf = *p;
|
|
|
|
// warn in debug build if buffer not aligned
|
|
#ifndef NDEBUG
|
|
size_t buf_misalign = ((uintptr_t)buf) % BLOCK_SIZE;
|
|
if(misalign != buf_misalign)
|
|
debug_out("file_io: warning: buffer %p and offset %x are misaligned", buf, raw_ofs);
|
|
#endif
|
|
}
|
|
// requesting we allocate the buffer
|
|
else
|
|
{
|
|
size_t buf_size = round_up(misalign + raw_size, BLOCK_SIZE);
|
|
our_buf = mem_alloc(buf_size, BLOCK_SIZE);
|
|
if(!our_buf)
|
|
return ERR_NO_MEM;
|
|
buf = our_buf;
|
|
*p = (char*)buf + misalign;
|
|
}
|
|
}
|
|
|
|
// buf is now the source or sink, regardless of who allocated it.
|
|
// we need to keep our_buf (memory we allocated), so we can free
|
|
// it if we fail; it's 0 if the caller passed in a buffer.
|
|
|
|
|
|
//
|
|
// now we read the file in 64 KB chunks, N-buffered.
|
|
// if reading from Zip, inflate while reading the next block.
|
|
//
|
|
|
|
const int MAX_IOS = 2;
|
|
Handle ios[MAX_IOS] = { 0 };
|
|
|
|
int head = 0;
|
|
int tail = 0;
|
|
int pending_ios = 0;
|
|
|
|
bool all_issued = false;
|
|
|
|
// (useful, raw data: possibly compressed, but doesn't count padding)
|
|
size_t raw_transferred_cnt = 0;
|
|
size_t issue_cnt = 0;
|
|
|
|
// if callback, what it reports; otherwise, = raw_transferred_cnt
|
|
// this is what we'll return
|
|
size_t actual_transferred_cnt = 0;
|
|
|
|
ssize_t err = +1; // loop terminates if <= 0
|
|
|
|
|
|
for(;;)
|
|
{
|
|
// queue not full, data remaining to transfer, and no error:
|
|
// start transferring next block.
|
|
if(pending_ios < MAX_IOS && !all_issued && err > 0)
|
|
{
|
|
// calculate issue_size:
|
|
// at most, transfer up to the next block boundary.
|
|
off_t issue_ofs = (off_t)(start_ofs + issue_cnt);
|
|
const size_t left_in_block = BLOCK_SIZE - (issue_ofs % BLOCK_SIZE);
|
|
const size_t total_left = raw_size - issue_cnt;
|
|
size_t issue_size = MIN(left_in_block, total_left);
|
|
|
|
// assume temp buffer allocated by file_start_io
|
|
void* data = 0;
|
|
// if transferring to/from normal file, use buf instead
|
|
if(buf)
|
|
data = (void*)((uintptr_t)buf + issue_cnt);
|
|
|
|
Handle hio = file_start_io(f, issue_ofs, issue_size, data);
|
|
if(hio <= 0)
|
|
err = (ssize_t)hio;
|
|
// transfer failed - loop will now terminate after
|
|
// waiting for all pending transfers to complete.
|
|
|
|
issue_cnt += issue_size;
|
|
if(issue_cnt >= raw_size)
|
|
all_issued = true;
|
|
|
|
// store IO in ring buffer
|
|
ios[head] = hio;
|
|
head = (head + 1) % MAX_IOS;
|
|
pending_ios++;
|
|
}
|
|
// IO pending: wait for it to complete, and process it.
|
|
else if(pending_ios)
|
|
{
|
|
Handle& hio = ios[tail];
|
|
tail = (tail + 1) % MAX_IOS;
|
|
pending_ios--;
|
|
|
|
void* block;
|
|
size_t size;
|
|
int ret = file_wait_io(hio, block, size);
|
|
if(ret < 0)
|
|
err = (ssize_t)ret;
|
|
|
|
//// if size comes out short, we must be at EOF
|
|
|
|
raw_transferred_cnt += size;
|
|
|
|
if(cb && !(err <= 0))
|
|
{
|
|
ssize_t ret = cb(ctx, block, size);
|
|
// if negative: processing failed; if 0, callback is finished.
|
|
// either way, loop will now terminate after waiting for all
|
|
// pending transfers to complete.
|
|
if(ret <= 0)
|
|
err = ret;
|
|
else
|
|
actual_transferred_cnt += ret;
|
|
}
|
|
// no callback to process data: raw = actual
|
|
else
|
|
actual_transferred_cnt += size;
|
|
|
|
file_discard_io(hio); // zeroes array entry
|
|
}
|
|
// (all issued OR error) AND no pending transfers - done.
|
|
else
|
|
break;
|
|
}
|
|
|
|
// failed (0 means callback reports it's finished)
|
|
if(err < 0)
|
|
{
|
|
// user didn't specify output buffer - free what we allocated,
|
|
// and clear 'out', which points to the freed buffer.
|
|
if(our_buf)
|
|
{
|
|
mem_free(our_buf);
|
|
*p = 0;
|
|
// we only allocate if p && *p, but had set *p above.
|
|
}
|
|
return err;
|
|
}
|
|
|
|
assert(issue_cnt == raw_transferred_cnt && raw_transferred_cnt == raw_size);
|
|
|
|
return (ssize_t)actual_transferred_cnt;
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// memory mapping
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
// no significance aside from preventing uint overflow.
|
|
static const uint MAX_MAP_REFS = 255;
|
|
|
|
|
|
// map the entire file <f> into memory. if already currently mapped,
|
|
// return the previous mapping (reference-counted).
|
|
// output parameters are zeroed on failure.
|
|
//
|
|
// the mapping will be removed (if still open) when its file is closed.
|
|
// however, map/unmap calls should still be paired so that the mapping
|
|
// may be removed when no longer needed.
|
|
//
|
|
// rationale: reference counting is required for zip_map: several
|
|
// Zip "mappings" each reference one ZArchive's actual file mapping.
|
|
// implement it here so that we also get refcounting for normal files.
|
|
int file_map(File* const f, void*& p, size_t& size)
|
|
{
|
|
p = 0;
|
|
size = 0;
|
|
|
|
CHECK_FILE(f);
|
|
|
|
// already mapped - increase refcount and return previous mapping.
|
|
if(f->mapping)
|
|
{
|
|
// prevent overflow; if we have this many refs, should find out why.
|
|
if(f->map_refs >= MAX_MAP_REFS)
|
|
{
|
|
debug_warn("file_map: too many references to mapping");
|
|
return -1;
|
|
}
|
|
f->map_refs++;
|
|
goto have_mapping;
|
|
}
|
|
|
|
const int prot = (f->flags & FILE_WRITE)? PROT_WRITE : PROT_READ;
|
|
f->mapping = mmap((void*)0, f->size, prot, MAP_PRIVATE, f->fd, (off_t)0);
|
|
if(!f->mapping)
|
|
return ERR_NO_MEM;
|
|
|
|
f->map_refs = 1;
|
|
|
|
have_mapping:
|
|
p = f->mapping;
|
|
size = f->size;
|
|
return 0;
|
|
}
|
|
|
|
|
|
// decrement the reference count for the mapping belonging to file <f>.
|
|
// fail if there are no references; remove the mapping if the count reaches 0.
|
|
//
|
|
// the mapping will be removed (if still open) when its file is closed.
|
|
// however, map/unmap calls should still be paired so that the mapping
|
|
// may be removed when no longer needed.
|
|
int file_unmap(File* const f)
|
|
{
|
|
CHECK_FILE(f);
|
|
|
|
// file is not currently mapped
|
|
if(f->map_refs == 0)
|
|
return -1;
|
|
|
|
// still more than one reference remaining - done.
|
|
if(--f->map_refs > 0)
|
|
return 0;
|
|
|
|
// no more references: remove the mapping
|
|
void* const p = f->mapping;
|
|
f->mapping = 0;
|
|
// don't clear f->size - the file is still open.
|
|
|
|
return munmap(p, f->size);
|
|
}
|