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, Error &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, Error &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, Error &error) {
64   if (fd == UINT64_MAX) {
65     error.SetErrorString("invalid file descriptor");
66     return UINT64_MAX;
67   }
68   FDToFileMap::iterator pos = m_cache.find(fd);
69   if (pos == m_cache.end()) {
70     error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
71     return false;
72   }
73   FileSP file_sp = pos->second;
74   if (!file_sp) {
75     error.SetErrorString("invalid host backing file");
76     return UINT64_MAX;
77   }
78   if (static_cast<uint64_t>(file_sp->SeekFromStart(offset, &error)) != offset ||
79       error.Fail())
80     return UINT64_MAX;
81   size_t bytes_written = src_len;
82   error = file_sp->Write(src, bytes_written);
83   if (error.Fail())
84     return UINT64_MAX;
85   return bytes_written;
86 }
87 
88 uint64_t FileCache::ReadFile(lldb::user_id_t fd, uint64_t offset, void *dst,
89                              uint64_t dst_len, Error &error) {
90   if (fd == UINT64_MAX) {
91     error.SetErrorString("invalid file descriptor");
92     return UINT64_MAX;
93   }
94   FDToFileMap::iterator pos = m_cache.find(fd);
95   if (pos == m_cache.end()) {
96     error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
97     return false;
98   }
99   FileSP file_sp = pos->second;
100   if (!file_sp) {
101     error.SetErrorString("invalid host backing file");
102     return UINT64_MAX;
103   }
104   if (static_cast<uint64_t>(file_sp->SeekFromStart(offset, &error)) != offset ||
105       error.Fail())
106     return UINT64_MAX;
107   size_t bytes_read = dst_len;
108   error = file_sp->Read(dst, bytes_read);
109   if (error.Fail())
110     return UINT64_MAX;
111   return bytes_read;
112 }
113