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 &
20 FileCache::GetInstance()
21 {
22     if (m_instance == nullptr)
23         m_instance = new FileCache();
24 
25     return *m_instance;
26 }
27 
28 lldb::user_id_t
29 FileCache::OpenFile(const FileSpec &file_spec, uint32_t flags, uint32_t mode, Error &error)
30 {
31     std::string path(file_spec.GetPath());
32     if (path.empty())
33     {
34         error.SetErrorString("empty path");
35         return UINT64_MAX;
36     }
37     FileSP file_sp(new File());
38     error = file_sp->Open(path.c_str(), flags, mode);
39     if (file_sp->IsValid() == false)
40         return UINT64_MAX;
41     lldb::user_id_t fd = file_sp->GetDescriptor();
42     m_cache[fd] = file_sp;
43     return fd;
44 }
45 
46 bool
47 FileCache::CloseFile(lldb::user_id_t fd, Error &error)
48 {
49     if (fd == UINT64_MAX)
50     {
51         error.SetErrorString("invalid file descriptor");
52         return false;
53     }
54     FDToFileMap::iterator pos = m_cache.find(fd);
55     if (pos == m_cache.end())
56     {
57         error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
58         return false;
59     }
60     FileSP file_sp = pos->second;
61     if (!file_sp)
62     {
63         error.SetErrorString("invalid host backing file");
64         return false;
65     }
66     error = file_sp->Close();
67     m_cache.erase(pos);
68     return error.Success();
69 }
70 
71 uint64_t
72 FileCache::WriteFile(lldb::user_id_t fd, uint64_t offset, const void *src, uint64_t src_len, Error &error)
73 {
74     if (fd == UINT64_MAX)
75     {
76         error.SetErrorString("invalid file descriptor");
77         return UINT64_MAX;
78     }
79     FDToFileMap::iterator pos = m_cache.find(fd);
80     if (pos == m_cache.end())
81     {
82         error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
83         return false;
84     }
85     FileSP file_sp = pos->second;
86     if (!file_sp)
87     {
88         error.SetErrorString("invalid host backing file");
89         return UINT64_MAX;
90     }
91     if (static_cast<uint64_t>(file_sp->SeekFromStart(offset, &error)) != offset || error.Fail())
92         return UINT64_MAX;
93     size_t bytes_written = src_len;
94     error = file_sp->Write(src, bytes_written);
95     if (error.Fail())
96         return UINT64_MAX;
97     return bytes_written;
98 }
99 
100 uint64_t
101 FileCache::ReadFile(lldb::user_id_t fd, uint64_t offset, void *dst, uint64_t dst_len, Error &error)
102 {
103     if (fd == UINT64_MAX)
104     {
105         error.SetErrorString("invalid file descriptor");
106         return UINT64_MAX;
107     }
108     FDToFileMap::iterator pos = m_cache.find(fd);
109     if (pos == m_cache.end())
110     {
111         error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
112         return false;
113     }
114     FileSP file_sp = pos->second;
115     if (!file_sp)
116     {
117         error.SetErrorString("invalid host backing file");
118         return UINT64_MAX;
119     }
120     if (static_cast<uint64_t>(file_sp->SeekFromStart(offset, &error)) != offset || error.Fail())
121         return UINT64_MAX;
122     size_t bytes_read = dst_len;
123     error = file_sp->Read(dst, bytes_read);
124     if (error.Fail())
125         return UINT64_MAX;
126     return bytes_read;
127 }
128