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forked from 0ad/0ad
0ad/source/ps/Mod.cpp
wraitii 87a2c3347f Make real directory paths on the VFS predictable (retry)
This is the same commit as 4bb31f084e, reverted in 5d1899785a. Noted
issues were fixed.

Partial revert/fix of 2f19cf86d3 and 2567fee329.

Before this diff, it was possible for a mod containing a cache/ or a
config/ folder to get written to incorrectly.
The issue is VFS can map multiple directories to one 'virtual' path, for
reading mods. However, writing data is problematic: which path to
choose?
The only viable solution is to use a path relative to the highest
priority directory encountered in the VFS path, or write paths could be
'hijacked' by lower-priority mods.

This fixes these issues by:
- Adding a new lookup mode ('Real-path') that explicitly picks the real
path relative to the highest-priority subdirectory in the VFS Path.
- Preventing overwriting a real directory with a lower priority one in
general.
- Revert c0c8132dd4's GetRealPath change, re-introducing the function as
GetOriginalPath.

This also cleans up some duplication that led to empty mod folders in
the user mod path, and cleans up loading the 'user' mod.
It also makes it explicit that a directory must be passed to Mount().

Note that the new 'realpath' lookup can still be somewhat complex with
many mount points at various hierarchy levels, but it is at least
predictable/deterministic without having to be careful about populating
order.

Fixes #2553

Differential Revision: https://code.wildfiregames.com/D3728
This was SVN commit r25107.
2021-03-23 12:46:59 +00:00

157 lines
4.5 KiB
C++

/* Copyright (C) 2021 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
#include "precompiled.h"
#include "ps/Mod.h"
#include <algorithm>
#include "lib/file/file_system.h"
#include "lib/file/vfs/vfs.h"
#include "lib/utf8.h"
#include "ps/Filesystem.h"
#include "ps/GameSetup/GameSetup.h"
#include "ps/GameSetup/Paths.h"
#include "ps/Pyrogenesis.h"
#include "scriptinterface/ScriptInterface.h"
std::vector<CStr> g_modsLoaded;
std::vector<std::vector<CStr>> g_LoadedModVersions;
CmdLineArgs g_args;
JS::Value Mod::GetAvailableMods(const ScriptInterface& scriptInterface)
{
ScriptRequest rq(scriptInterface);
JS::RootedObject obj(rq.cx, JS_NewPlainObject(rq.cx));
const Paths paths(g_args);
// loop over all possible paths
OsPath modPath = paths.RData()/"mods";
OsPath modUserPath = paths.UserData()/"mods";
DirectoryNames modDirs;
DirectoryNames modDirsUser;
GetDirectoryEntries(modPath, NULL, &modDirs);
// Sort modDirs so that we can do a fast lookup below
std::sort(modDirs.begin(), modDirs.end());
PIVFS vfs = CreateVfs();
for (DirectoryNames::iterator iter = modDirs.begin(); iter != modDirs.end(); ++iter)
{
vfs->Clear();
// Mount with lowest priority, we don't want to overwrite anything
if (vfs->Mount(L"", modPath / *iter / "", VFS_MOUNT_MUST_EXIST, VFS_MIN_PRIORITY) < 0)
continue;
CVFSFile modinfo;
if (modinfo.Load(vfs, L"mod.json", false) != PSRETURN_OK)
continue;
JS::RootedValue json(rq.cx);
if (!scriptInterface.ParseJSON(modinfo.GetAsString(), &json))
continue;
// Valid mod, add it to our structure
JS_SetProperty(rq.cx, obj, utf8_from_wstring(iter->string()).c_str(), json);
}
GetDirectoryEntries(modUserPath, NULL, &modDirsUser);
bool dev = InDevelopmentCopy();
for (DirectoryNames::iterator iter = modDirsUser.begin(); iter != modDirsUser.end(); ++iter)
{
// If we are in a dev copy we do not mount mods in the user mod folder that
// are already present in the mod folder, thus we skip those here.
if (dev && std::binary_search(modDirs.begin(), modDirs.end(), *iter))
continue;
vfs->Clear();
// Mount with lowest priority, we don't want to overwrite anything
if (vfs->Mount(L"", modUserPath / *iter / "", VFS_MOUNT_MUST_EXIST, VFS_MIN_PRIORITY) < 0)
continue;
CVFSFile modinfo;
if (modinfo.Load(vfs, L"mod.json", false) != PSRETURN_OK)
continue;
JS::RootedValue json(rq.cx);
if (!scriptInterface.ParseJSON(modinfo.GetAsString(), &json))
continue;
// Valid mod, add it to our structure
JS_SetProperty(rq.cx, obj, utf8_from_wstring(iter->string()).c_str(), json);
}
return JS::ObjectValue(*obj);
}
void Mod::CacheEnabledModVersions(const shared_ptr<ScriptContext>& scriptContext)
{
ScriptInterface scriptInterface("Engine", "CacheEnabledModVersions", scriptContext);
ScriptRequest rq(scriptInterface);
JS::RootedValue availableMods(rq.cx, GetAvailableMods(scriptInterface));
g_LoadedModVersions.clear();
for (const CStr& mod : g_modsLoaded)
{
// Ignore mod mod as it is irrelevant for compatibility checks
if (mod == "mod")
continue;
CStr version;
JS::RootedValue modData(rq.cx);
if (scriptInterface.GetProperty(availableMods, mod.c_str(), &modData))
scriptInterface.GetProperty(modData, "version", version);
g_LoadedModVersions.push_back({mod, version});
}
}
JS::Value Mod::GetLoadedModsWithVersions(const ScriptInterface& scriptInterface)
{
ScriptRequest rq(scriptInterface);
JS::RootedValue returnValue(rq.cx);
scriptInterface.ToJSVal(rq, &returnValue, g_LoadedModVersions);
return returnValue;
}
JS::Value Mod::GetEngineInfo(const ScriptInterface& scriptInterface)
{
ScriptRequest rq(scriptInterface);
JS::RootedValue mods(rq.cx, Mod::GetLoadedModsWithVersions(scriptInterface));
JS::RootedValue metainfo(rq.cx);
ScriptInterface::CreateObject(
rq,
&metainfo,
"engine_version", engine_version,
"mods", mods);
scriptInterface.FreezeObject(metainfo, true);
return metainfo;
}