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 "SourceCode.h"
11 #include "support/Logger.h"
12 #include "llvm/ADT/StringExtras.h"
13 #include "llvm/Support/Errc.h"
14 #include "llvm/Support/VirtualFileSystem.h"
15 #include <memory>
16
17 namespace clang {
18 namespace clangd {
19
getDraft(PathRef File) const20 llvm::Optional<DraftStore::Draft> DraftStore::getDraft(PathRef File) const {
21 std::lock_guard<std::mutex> Lock(Mutex);
22
23 auto It = Drafts.find(File);
24 if (It == Drafts.end())
25 return None;
26
27 return It->second.D;
28 }
29
getActiveFiles() const30 std::vector<Path> DraftStore::getActiveFiles() const {
31 std::lock_guard<std::mutex> Lock(Mutex);
32 std::vector<Path> ResultVector;
33
34 for (auto DraftIt = Drafts.begin(); DraftIt != Drafts.end(); DraftIt++)
35 ResultVector.push_back(std::string(DraftIt->getKey()));
36
37 return ResultVector;
38 }
39
increment(std::string & S)40 static void increment(std::string &S) {
41 // Ensure there is a numeric suffix.
42 if (S.empty() || !llvm::isDigit(S.back())) {
43 S.push_back('0');
44 return;
45 }
46 // Increment the numeric suffix.
47 auto I = S.rbegin(), E = S.rend();
48 for (;;) {
49 if (I == E || !llvm::isDigit(*I)) {
50 // Reached start of numeric section, it was all 9s.
51 S.insert(I.base(), '1');
52 break;
53 }
54 if (*I != '9') {
55 // Found a digit we can increment, we're done.
56 ++*I;
57 break;
58 }
59 *I = '0'; // and keep incrementing to the left.
60 }
61 }
62
updateVersion(DraftStore::Draft & D,llvm::StringRef SpecifiedVersion)63 static void updateVersion(DraftStore::Draft &D,
64 llvm::StringRef SpecifiedVersion) {
65 if (!SpecifiedVersion.empty()) {
66 // We treat versions as opaque, but the protocol says they increase.
67 if (SpecifiedVersion.compare_numeric(D.Version) <= 0)
68 log("File version went from {0} to {1}", D.Version, SpecifiedVersion);
69 D.Version = SpecifiedVersion.str();
70 } else {
71 // Note that if D was newly-created, this will bump D.Version from "" to 1.
72 increment(D.Version);
73 }
74 }
75
addDraft(PathRef File,llvm::StringRef Version,llvm::StringRef Contents)76 std::string DraftStore::addDraft(PathRef File, llvm::StringRef Version,
77 llvm::StringRef Contents) {
78 std::lock_guard<std::mutex> Lock(Mutex);
79
80 auto &D = Drafts[File];
81 updateVersion(D.D, Version);
82 std::time(&D.MTime);
83 D.D.Contents = std::make_shared<std::string>(Contents);
84 return D.D.Version;
85 }
86
removeDraft(PathRef File)87 void DraftStore::removeDraft(PathRef File) {
88 std::lock_guard<std::mutex> Lock(Mutex);
89
90 Drafts.erase(File);
91 }
92
93 namespace {
94
95 /// A read only MemoryBuffer shares ownership of a ref counted string. The
96 /// shared string object must not be modified while an owned by this buffer.
97 class SharedStringBuffer : public llvm::MemoryBuffer {
98 const std::shared_ptr<const std::string> BufferContents;
99 const std::string Name;
100
101 public:
getBufferKind() const102 BufferKind getBufferKind() const override {
103 return MemoryBuffer::MemoryBuffer_Malloc;
104 }
105
getBufferIdentifier() const106 StringRef getBufferIdentifier() const override { return Name; }
107
SharedStringBuffer(std::shared_ptr<const std::string> Data,StringRef Name)108 SharedStringBuffer(std::shared_ptr<const std::string> Data, StringRef Name)
109 : BufferContents(std::move(Data)), Name(Name) {
110 assert(BufferContents && "Can't create from empty shared_ptr");
111 MemoryBuffer::init(BufferContents->c_str(),
112 BufferContents->c_str() + BufferContents->size(),
113 /*RequiresNullTerminator=*/true);
114 }
115 };
116 } // namespace
117
asVFS() const118 llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> DraftStore::asVFS() const {
119 auto MemFS = llvm::makeIntrusiveRefCnt<llvm::vfs::InMemoryFileSystem>();
120 std::lock_guard<std::mutex> Guard(Mutex);
121 for (const auto &Draft : Drafts)
122 MemFS->addFile(Draft.getKey(), Draft.getValue().MTime,
123 std::make_unique<SharedStringBuffer>(
124 Draft.getValue().D.Contents, Draft.getKey()));
125 return MemFS;
126 }
127 } // namespace clangd
128 } // namespace clang
129