1 //===-- FileCache.cpp -------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Host/FileCache.h"
11 
12 #include "lldb/Host/File.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, uint32_t flags,
27                                     uint32_t mode, Status &error) {
28   std::string path(file_spec.GetPath());
29   if (path.empty()) {
30     error.SetErrorString("empty path");
31     return UINT64_MAX;
32   }
33   FileSP file_sp(new File());
34   error = file_sp->Open(path.c_str(), flags, mode);
35   if (file_sp->IsValid() == false)
36     return UINT64_MAX;
37   lldb::user_id_t fd = file_sp->GetDescriptor();
38   m_cache[fd] = file_sp;
39   return fd;
40 }
41 
42 bool FileCache::CloseFile(lldb::user_id_t fd, Status &error) {
43   if (fd == UINT64_MAX) {
44     error.SetErrorString("invalid file descriptor");
45     return false;
46   }
47   FDToFileMap::iterator pos = m_cache.find(fd);
48   if (pos == m_cache.end()) {
49     error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
50     return false;
51   }
52   FileSP file_sp = pos->second;
53   if (!file_sp) {
54     error.SetErrorString("invalid host backing file");
55     return false;
56   }
57   error = file_sp->Close();
58   m_cache.erase(pos);
59   return error.Success();
60 }
61 
62 uint64_t FileCache::WriteFile(lldb::user_id_t fd, uint64_t offset,
63                               const void *src, uint64_t src_len,
64                               Status &error) {
65   if (fd == UINT64_MAX) {
66     error.SetErrorString("invalid file descriptor");
67     return UINT64_MAX;
68   }
69   FDToFileMap::iterator pos = m_cache.find(fd);
70   if (pos == m_cache.end()) {
71     error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
72     return false;
73   }
74   FileSP file_sp = pos->second;
75   if (!file_sp) {
76     error.SetErrorString("invalid host backing file");
77     return UINT64_MAX;
78   }
79   if (static_cast<uint64_t>(file_sp->SeekFromStart(offset, &error)) != offset ||
80       error.Fail())
81     return UINT64_MAX;
82   size_t bytes_written = src_len;
83   error = file_sp->Write(src, bytes_written);
84   if (error.Fail())
85     return UINT64_MAX;
86   return bytes_written;
87 }
88 
89 uint64_t FileCache::ReadFile(lldb::user_id_t fd, uint64_t offset, void *dst,
90                              uint64_t dst_len, Status &error) {
91   if (fd == UINT64_MAX) {
92     error.SetErrorString("invalid file descriptor");
93     return UINT64_MAX;
94   }
95   FDToFileMap::iterator pos = m_cache.find(fd);
96   if (pos == m_cache.end()) {
97     error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
98     return false;
99   }
100   FileSP file_sp = pos->second;
101   if (!file_sp) {
102     error.SetErrorString("invalid host backing file");
103     return UINT64_MAX;
104   }
105   if (static_cast<uint64_t>(file_sp->SeekFromStart(offset, &error)) != offset ||
106       error.Fail())
107     return UINT64_MAX;
108   size_t bytes_read = dst_len;
109   error = file_sp->Read(dst, bytes_read);
110   if (error.Fail())
111     return UINT64_MAX;
112   return bytes_read;
113 }
114