BackgroundIndexStorage.cpp
5.43 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
//== BackgroundIndexStorage.cpp - Provide caching support to BackgroundIndex ==/
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "GlobalCompilationDatabase.h"
#include "index/Background.h"
#include "support/Logger.h"
#include "support/Path.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include <functional>
namespace clang {
namespace clangd {
namespace {
std::string getShardPathFromFilePath(llvm::StringRef ShardRoot,
llvm::StringRef FilePath) {
llvm::SmallString<128> ShardRootSS(ShardRoot);
llvm::sys::path::append(ShardRootSS, llvm::sys::path::filename(FilePath) +
"." + llvm::toHex(digest(FilePath)) +
".idx");
return std::string(ShardRootSS.str());
}
// Uses disk as a storage for index shards.
class DiskBackedIndexStorage : public BackgroundIndexStorage {
std::string DiskShardRoot;
public:
// Creates `DiskShardRoot` and any parents during construction.
DiskBackedIndexStorage(llvm::StringRef Directory) : DiskShardRoot(Directory) {
std::error_code OK;
std::error_code EC = llvm::sys::fs::create_directories(DiskShardRoot);
if (EC != OK) {
elog("Failed to create directory {0} for index storage: {1}",
DiskShardRoot, EC.message());
}
}
std::unique_ptr<IndexFileIn>
loadShard(llvm::StringRef ShardIdentifier) const override {
const std::string ShardPath =
getShardPathFromFilePath(DiskShardRoot, ShardIdentifier);
auto Buffer = llvm::MemoryBuffer::getFile(ShardPath);
if (!Buffer)
return nullptr;
if (auto I = readIndexFile(Buffer->get()->getBuffer()))
return std::make_unique<IndexFileIn>(std::move(*I));
else
elog("Error while reading shard {0}: {1}", ShardIdentifier,
I.takeError());
return nullptr;
}
llvm::Error storeShard(llvm::StringRef ShardIdentifier,
IndexFileOut Shard) const override {
auto ShardPath = getShardPathFromFilePath(DiskShardRoot, ShardIdentifier);
return llvm::writeFileAtomically(ShardPath + ".tmp.%%%%%%%%", ShardPath,
[&Shard](llvm::raw_ostream &OS) {
OS << Shard;
return llvm::Error::success();
});
}
};
// Doesn't persist index shards anywhere (used when the CDB dir is unknown).
// We could consider indexing into ~/.clangd/ or so instead.
class NullStorage : public BackgroundIndexStorage {
public:
std::unique_ptr<IndexFileIn>
loadShard(llvm::StringRef ShardIdentifier) const override {
return nullptr;
}
llvm::Error storeShard(llvm::StringRef ShardIdentifier,
IndexFileOut Shard) const override {
vlog("Couldn't find project for {0}, indexing in-memory only",
ShardIdentifier);
return llvm::Error::success();
}
};
// Creates and owns IndexStorages for multiple CDBs.
// When a CDB root is found, shards are stored in $ROOT/.cache/clangd/index/.
// When no root is found, the fallback path is ~/.cache/clangd/index/.
class DiskBackedIndexStorageManager {
public:
DiskBackedIndexStorageManager(
std::function<llvm::Optional<ProjectInfo>(PathRef)> GetProjectInfo)
: IndexStorageMapMu(std::make_unique<std::mutex>()),
GetProjectInfo(std::move(GetProjectInfo)) {
llvm::SmallString<128> FallbackDir;
if (llvm::sys::path::cache_directory(FallbackDir))
llvm::sys::path::append(FallbackDir, "clangd", "index");
this->FallbackDir = FallbackDir.str().str();
}
// Creates or fetches to storage from cache for the specified project.
BackgroundIndexStorage *operator()(PathRef File) {
std::lock_guard<std::mutex> Lock(*IndexStorageMapMu);
llvm::SmallString<128> StorageDir(FallbackDir);
if (auto PI = GetProjectInfo(File)) {
StorageDir = PI->SourceRoot;
llvm::sys::path::append(StorageDir, ".cache", "clangd", "index");
}
auto &IndexStorage = IndexStorageMap[StorageDir];
if (!IndexStorage)
IndexStorage = create(StorageDir);
return IndexStorage.get();
}
private:
std::unique_ptr<BackgroundIndexStorage> create(PathRef CDBDirectory) {
if (CDBDirectory.empty()) {
elog("Tried to create storage for empty directory!");
return std::make_unique<NullStorage>();
}
return std::make_unique<DiskBackedIndexStorage>(CDBDirectory);
}
Path FallbackDir;
llvm::StringMap<std::unique_ptr<BackgroundIndexStorage>> IndexStorageMap;
std::unique_ptr<std::mutex> IndexStorageMapMu;
std::function<llvm::Optional<ProjectInfo>(PathRef)> GetProjectInfo;
};
} // namespace
BackgroundIndexStorage::Factory
BackgroundIndexStorage::createDiskBackedStorageFactory(
std::function<llvm::Optional<ProjectInfo>(PathRef)> GetProjectInfo) {
return DiskBackedIndexStorageManager(std::move(GetProjectInfo));
}
} // namespace clangd
} // namespace clang