LLDB  mainline
FileCache.cpp
Go to the documentation of this file.
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 
14 using namespace lldb;
15 using namespace lldb_private;
16 
17 FileCache *FileCache::m_instance = nullptr;
18 
19 FileCache &FileCache::GetInstance() {
20  if (m_instance == nullptr)
21  m_instance = new FileCache();
22 
23  return *m_instance;
24 }
25 
26 lldb::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.SetErrorString("empty path");
31  return UINT64_MAX;
32  }
33  auto file = FileSystem::Instance().Open(file_spec, flags, mode);
34  if (!file) {
35  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 
43 bool FileCache::CloseFile(lldb::user_id_t fd, Status &error) {
44  if (fd == UINT64_MAX) {
45  error.SetErrorString("invalid file descriptor");
46  return false;
47  }
48  FDToFileMap::iterator pos = m_cache.find(fd);
49  if (pos == m_cache.end()) {
50  error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
51  return false;
52  }
53  FileUP &file_up = pos->second;
54  if (!file_up) {
55  error.SetErrorString("invalid host backing file");
56  return false;
57  }
58  error = file_up->Close();
59  m_cache.erase(pos);
60  return error.Success();
61 }
62 
63 uint64_t FileCache::WriteFile(lldb::user_id_t fd, uint64_t offset,
64  const void *src, uint64_t src_len,
65  Status &error) {
66  if (fd == UINT64_MAX) {
67  error.SetErrorString("invalid file descriptor");
68  return UINT64_MAX;
69  }
70  FDToFileMap::iterator pos = m_cache.find(fd);
71  if (pos == m_cache.end()) {
72  error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
73  return false;
74  }
75  FileUP &file_up = pos->second;
76  if (!file_up) {
77  error.SetErrorString("invalid host backing file");
78  return UINT64_MAX;
79  }
80  if (static_cast<uint64_t>(file_up->SeekFromStart(offset, &error)) != offset ||
81  error.Fail())
82  return UINT64_MAX;
83  size_t bytes_written = src_len;
84  error = file_up->Write(src, bytes_written);
85  if (error.Fail())
86  return UINT64_MAX;
87  return bytes_written;
88 }
89 
90 uint64_t FileCache::ReadFile(lldb::user_id_t fd, uint64_t offset, void *dst,
91  uint64_t dst_len, Status &error) {
92  if (fd == UINT64_MAX) {
93  error.SetErrorString("invalid file descriptor");
94  return UINT64_MAX;
95  }
96  FDToFileMap::iterator pos = m_cache.find(fd);
97  if (pos == m_cache.end()) {
98  error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
99  return false;
100  }
101  FileUP &file_up = pos->second;
102  if (!file_up) {
103  error.SetErrorString("invalid host backing file");
104  return UINT64_MAX;
105  }
106  if (static_cast<uint64_t>(file_up->SeekFromStart(offset, &error)) != offset ||
107  error.Fail())
108  return UINT64_MAX;
109  size_t bytes_read = dst_len;
110  error = file_up->Read(dst, bytes_read);
111  if (error.Fail())
112  return UINT64_MAX;
113  return bytes_read;
114 }
A class that represents a running process on the host machine.
A file utility class.
Definition: FileSpec.h:56
uint64_t user_id_t
Definition: lldb-types.h:84
static llvm::raw_ostream & error(Stream &strm)
void SetErrorString(llvm::StringRef err_str)
Set the current error string to err_str.
Definition: Status.cpp:242
bool Success() const
Test for success condition.
Definition: Status.cpp:288
bool Fail() const
Test for error condition.
Definition: Status.cpp:182
Definition: SBAddress.h:15
int SetErrorStringWithFormat(const char *format,...) __attribute__((format(printf
Set the current error string to a formatted error string.
Definition: Status.cpp:256
#define UINT64_MAX
Definition: lldb-defines.h:35
An error handling class.
Definition: Status.h:44