1 | //===--- RIFF.cpp - Binary container file format --------------------------===// |
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 "RIFF.h" |
10 | #include "support/Logger.h" |
11 | #include "llvm/Support/Endian.h" |
12 | |
13 | namespace clang { |
14 | namespace clangd { |
15 | namespace riff { |
16 | |
17 | llvm::Expected<Chunk> readChunk(llvm::StringRef &Stream) { |
18 | if (Stream.size() < 8) |
19 | return error("incomplete chunk header: {0} bytes available" , Stream.size()); |
20 | Chunk C; |
21 | std::copy(Stream.begin(), Stream.begin() + 4, C.ID.begin()); |
22 | Stream = Stream.drop_front(4); |
23 | uint32_t Len = llvm::support::endian::read32le(Stream.take_front(4).begin()); |
24 | Stream = Stream.drop_front(4); |
25 | if (Stream.size() < Len) |
26 | return error("truncated chunk: want {0}, got {1}" , Len, Stream.size()); |
27 | C.Data = Stream.take_front(Len); |
28 | Stream = Stream.drop_front(Len); |
29 | if ((Len % 2) && !Stream.empty()) { // Skip padding byte. |
30 | if (Stream.front()) |
31 | return error("nonzero padding byte" ); |
32 | Stream = Stream.drop_front(); |
33 | } |
34 | return std::move(C); |
35 | } |
36 | |
37 | llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Chunk &C) { |
38 | OS.write(C.ID.data(), C.ID.size()); |
39 | char Size[4]; |
40 | llvm::support::endian::write32le(Size, C.Data.size()); |
41 | OS.write(Size, sizeof(Size)); |
42 | OS << C.Data; |
43 | if (C.Data.size() % 2) |
44 | OS.write(0); |
45 | return OS; |
46 | } |
47 | |
48 | llvm::Expected<File> readFile(llvm::StringRef Stream) { |
49 | auto RIFF = readChunk(Stream); |
50 | if (!RIFF) |
51 | return RIFF.takeError(); |
52 | if (RIFF->ID != fourCC("RIFF" )) |
53 | return error("not a RIFF container: root is {0}" , fourCCStr(RIFF->ID)); |
54 | if (RIFF->Data.size() < 4) |
55 | return error("RIFF chunk too short" ); |
56 | File F; |
57 | std::copy(RIFF->Data.begin(), RIFF->Data.begin() + 4, F.Type.begin()); |
58 | for (llvm::StringRef Body = RIFF->Data.drop_front(4); !Body.empty();) |
59 | if (auto Chunk = readChunk(Body)) { |
60 | F.Chunks.push_back(*Chunk); |
61 | } else |
62 | return Chunk.takeError(); |
63 | return std::move(F); |
64 | } |
65 | |
66 | llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const File &F) { |
67 | // To avoid copies, we serialize the outer RIFF chunk "by hand". |
68 | size_t DataLen = 4; // Predict length of RIFF chunk data. |
69 | for (const auto &C : F.Chunks) |
70 | DataLen += 4 + 4 + C.Data.size() + (C.Data.size() % 2); |
71 | OS << "RIFF" ; |
72 | char Size[4]; |
73 | llvm::support::endian::write32le(Size, DataLen); |
74 | OS.write(Size, sizeof(Size)); |
75 | OS.write(F.Type.data(), F.Type.size()); |
76 | for (const auto &C : F.Chunks) |
77 | OS << C; |
78 | return OS; |
79 | } |
80 | |
81 | } // namespace riff |
82 | } // namespace clangd |
83 | } // namespace clang |
84 | |