1 //===--- DraftStore.cpp - File contents container ---------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "DraftStore.h"
10 #include "support/Logger.h"
11 #include "llvm/ADT/StringExtras.h"
12 #include "llvm/Support/VirtualFileSystem.h"
13 #include <memory>
14 #include <optional>
15
16 namespace clang {
17 namespace clangd {
18
getDraft(PathRef File) const19 std::optional<DraftStore::Draft> DraftStore::getDraft(PathRef File) const {
20 std::lock_guard<std::mutex> Lock(Mutex);
21
22 auto It = Drafts.find(File);
23 if (It == Drafts.end())
24 return std::nullopt;
25
26 return It->second.D;
27 }
28
getActiveFiles() const29 std::vector<Path> DraftStore::getActiveFiles() const {
30 std::lock_guard<std::mutex> Lock(Mutex);
31 std::vector<Path> ResultVector;
32
33 for (auto DraftIt = Drafts.begin(); DraftIt != Drafts.end(); DraftIt++)
34 ResultVector.push_back(std::string(DraftIt->getKey()));
35
36 return ResultVector;
37 }
38
increment(std::string & S)39 static void increment(std::string &S) {
40 // Ensure there is a numeric suffix.
41 if (S.empty() || !llvm::isDigit(S.back())) {
42 S.push_back('0');
43 return;
44 }
45 // Increment the numeric suffix.
46 auto I = S.rbegin(), E = S.rend();
47 for (;;) {
48 if (I == E || !llvm::isDigit(*I)) {
49 // Reached start of numeric section, it was all 9s.
50 S.insert(I.base(), '1');
51 break;
52 }
53 if (*I != '9') {
54 // Found a digit we can increment, we're done.
55 ++*I;
56 break;
57 }
58 *I = '0'; // and keep incrementing to the left.
59 }
60 }
61
updateVersion(DraftStore::Draft & D,llvm::StringRef SpecifiedVersion)62 static void updateVersion(DraftStore::Draft &D,
63 llvm::StringRef SpecifiedVersion) {
64 if (!SpecifiedVersion.empty()) {
65 // We treat versions as opaque, but the protocol says they increase.
66 if (SpecifiedVersion.compare_numeric(D.Version) <= 0)
67 log("File version went from {0} to {1}", D.Version, SpecifiedVersion);
68 D.Version = SpecifiedVersion.str();
69 } else {
70 // Note that if D was newly-created, this will bump D.Version from "" to 1.
71 increment(D.Version);
72 }
73 }
74
addDraft(PathRef File,llvm::StringRef Version,llvm::StringRef Contents)75 std::string DraftStore::addDraft(PathRef File, llvm::StringRef Version,
76 llvm::StringRef Contents) {
77 std::lock_guard<std::mutex> Lock(Mutex);
78
79 auto &D = Drafts[File];
80 updateVersion(D.D, Version);
81 std::time(&D.MTime);
82 D.D.Contents = std::make_shared<std::string>(Contents);
83 return D.D.Version;
84 }
85
removeDraft(PathRef File)86 void DraftStore::removeDraft(PathRef File) {
87 std::lock_guard<std::mutex> Lock(Mutex);
88
89 Drafts.erase(File);
90 }
91
92 namespace {
93
94 /// A read only MemoryBuffer shares ownership of a ref counted string. The
95 /// shared string object must not be modified while an owned by this buffer.
96 class SharedStringBuffer : public llvm::MemoryBuffer {
97 const std::shared_ptr<const std::string> BufferContents;
98 const std::string Name;
99
100 public:
getBufferKind() const101 BufferKind getBufferKind() const override {
102 return MemoryBuffer::MemoryBuffer_Malloc;
103 }
104
getBufferIdentifier() const105 StringRef getBufferIdentifier() const override { return Name; }
106
SharedStringBuffer(std::shared_ptr<const std::string> Data,StringRef Name)107 SharedStringBuffer(std::shared_ptr<const std::string> Data, StringRef Name)
108 : BufferContents(std::move(Data)), Name(Name) {
109 assert(BufferContents && "Can't create from empty shared_ptr");
110 MemoryBuffer::init(BufferContents->c_str(),
111 BufferContents->c_str() + BufferContents->size(),
112 /*RequiresNullTerminator=*/true);
113 }
114 };
115 } // namespace
116
asVFS() const117 llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> DraftStore::asVFS() const {
118 auto MemFS = llvm::makeIntrusiveRefCnt<llvm::vfs::InMemoryFileSystem>();
119 std::lock_guard<std::mutex> Guard(Mutex);
120 for (const auto &Draft : Drafts)
121 MemFS->addFile(Draft.getKey(), Draft.getValue().MTime,
122 std::make_unique<SharedStringBuffer>(
123 Draft.getValue().D.Contents, Draft.getKey()));
124 return MemFS;
125 }
126 } // namespace clangd
127 } // namespace clang
128