1//===-- FileCache.cpp -----------------------------------------------------===//
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 "lldb/Host/FileCache.h"
10
11#include "lldb/Host/File.h"
12#include "lldb/Host/FileSystem.h"
13
14using namespace lldb;
15using namespace lldb_private;
16
17FileCache *FileCache::m_instance = nullptr;
18
19FileCache &FileCache::GetInstance() {
20 if (m_instance == nullptr)
21 m_instance = new FileCache();
22
23 return *m_instance;
24}
25
26lldb::user_id_t FileCache::OpenFile(const FileSpec &file_spec,
27 File::OpenOptions flags, uint32_t mode,
28 Status &error) {
29 if (!file_spec) {
30 error = Status::FromErrorString(str: "empty path");
31 return UINT64_MAX;
32 }
33 auto file = FileSystem::Instance().Open(file_spec, options: flags, permissions: mode);
34 if (!file) {
35 error = Status::FromError(error: file.takeError());
36 return UINT64_MAX;
37 }
38 lldb::user_id_t fd = file.get()->GetDescriptor();
39 m_cache[fd] = std::move(file.get());
40 return fd;
41}
42
43bool FileCache::CloseFile(lldb::user_id_t fd, Status &error) {
44 if (fd == UINT64_MAX) {
45 error = Status::FromErrorString(str: "invalid file descriptor");
46 return false;
47 }
48 FDToFileMap::iterator pos = m_cache.find(x: fd);
49 if (pos == m_cache.end()) {
50 error = Status::FromErrorStringWithFormat(
51 format: "invalid host file descriptor %" PRIu64, fd);
52 return false;
53 }
54 FileUP &file_up = pos->second;
55 if (!file_up) {
56 error = Status::FromErrorString(str: "invalid host backing file");
57 return false;
58 }
59 error = file_up->Close();
60 m_cache.erase(position: pos);
61 return error.Success();
62}
63
64uint64_t FileCache::WriteFile(lldb::user_id_t fd, uint64_t offset,
65 const void *src, uint64_t src_len,
66 Status &error) {
67 if (fd == UINT64_MAX) {
68 error = Status::FromErrorString(str: "invalid file descriptor");
69 return UINT64_MAX;
70 }
71 FDToFileMap::iterator pos = m_cache.find(x: fd);
72 if (pos == m_cache.end()) {
73 error = Status::FromErrorStringWithFormat(
74 format: "invalid host file descriptor %" PRIu64, fd);
75 return false;
76 }
77 FileUP &file_up = pos->second;
78 if (!file_up) {
79 error = Status::FromErrorString(str: "invalid host backing file");
80 return UINT64_MAX;
81 }
82 if (static_cast<uint64_t>(file_up->SeekFromStart(offset, error_ptr: &error)) != offset ||
83 error.Fail())
84 return UINT64_MAX;
85 size_t bytes_written = src_len;
86 error = file_up->Write(buf: src, num_bytes&: bytes_written);
87 if (error.Fail())
88 return UINT64_MAX;
89 return bytes_written;
90}
91
92uint64_t FileCache::ReadFile(lldb::user_id_t fd, uint64_t offset, void *dst,
93 uint64_t dst_len, Status &error) {
94 if (fd == UINT64_MAX) {
95 error = Status::FromErrorString(str: "invalid file descriptor");
96 return UINT64_MAX;
97 }
98 FDToFileMap::iterator pos = m_cache.find(x: fd);
99 if (pos == m_cache.end()) {
100 error = Status::FromErrorStringWithFormat(
101 format: "invalid host file descriptor %" PRIu64, fd);
102 return false;
103 }
104 FileUP &file_up = pos->second;
105 if (!file_up) {
106 error = Status::FromErrorString(str: "invalid host backing file");
107 return UINT64_MAX;
108 }
109 if (static_cast<uint64_t>(file_up->SeekFromStart(offset, error_ptr: &error)) != offset ||
110 error.Fail())
111 return UINT64_MAX;
112 size_t bytes_read = dst_len;
113 error = file_up->Read(buf: dst, num_bytes&: bytes_read);
114 if (error.Fail())
115 return UINT64_MAX;
116 return bytes_read;
117}
118

source code of lldb/source/Host/common/FileCache.cpp