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
16namespace clang {
17namespace clangd {
18
19std::optional<DraftStore::Draft> DraftStore::getDraft(PathRef File) const {
20 std::lock_guard<std::mutex> Lock(Mutex);
21
22 auto It = Drafts.find(Key: File);
23 if (It == Drafts.end())
24 return std::nullopt;
25
26 return It->second.D;
27}
28
29std::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(x: std::string(DraftIt->getKey()));
35
36 return ResultVector;
37}
38
39static void increment(std::string &S) {
40 // Ensure there is a numeric suffix.
41 if (S.empty() || !llvm::isDigit(C: S.back())) {
42 S.push_back(c: '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(C: *I)) {
49 // Reached start of numeric section, it was all 9s.
50 S.insert(p: I.base(), c: '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
62static 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(RHS: D.Version) <= 0)
67 log(Fmt: "File version went from {0} to {1}", Vals&: D.Version, Vals&: 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(S&: D.Version);
72 }
73}
74
75std::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.D, SpecifiedVersion: Version);
81 std::time(timer: &D.MTime);
82 D.D.Contents = std::make_shared<std::string>(args&: Contents);
83 return D.D.Version;
84}
85
86void DraftStore::removeDraft(PathRef File) {
87 std::lock_guard<std::mutex> Lock(Mutex);
88
89 Drafts.erase(Key: File);
90}
91
92namespace {
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.
96class SharedStringBuffer : public llvm::MemoryBuffer {
97 const std::shared_ptr<const std::string> BufferContents;
98 const std::string Name;
99
100public:
101 BufferKind getBufferKind() const override {
102 return MemoryBuffer::MemoryBuffer_Malloc;
103 }
104
105 StringRef getBufferIdentifier() const override { return Name; }
106
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(BufStart: BufferContents->c_str(),
111 BufEnd: BufferContents->c_str() + BufferContents->size(),
112 /*RequiresNullTerminator=*/true);
113 }
114};
115} // namespace
116
117llvm::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(Path: Draft.getKey(), ModificationTime: Draft.getValue().MTime,
122 Buffer: std::make_unique<SharedStringBuffer>(
123 args: Draft.getValue().D.Contents, args: Draft.getKey()));
124 return MemFS;
125}
126} // namespace clangd
127} // namespace clang
128

source code of clang-tools-extra/clangd/DraftStore.cpp