llvm-project/lldb/source/Host/common/FileCache.cpp

115 lines
3.4 KiB
C++

//===-- FileCache.cpp -----------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Host/FileCache.h"
#include "lldb/Host/File.h"
#include "lldb/Host/FileSystem.h"
using namespace lldb;
using namespace lldb_private;
FileCache *FileCache::m_instance = nullptr;
FileCache &FileCache::GetInstance() {
if (m_instance == nullptr)
m_instance = new FileCache();
return *m_instance;
}
lldb::user_id_t FileCache::OpenFile(const FileSpec &file_spec,
File::OpenOptions flags, uint32_t mode,
Status &error) {
if (!file_spec) {
error.SetErrorString("empty path");
return UINT64_MAX;
}
auto file = FileSystem::Instance().Open(file_spec, flags, mode);
if (!file) {
error = file.takeError();
return UINT64_MAX;
}
lldb::user_id_t fd = file.get()->GetDescriptor();
m_cache[fd] = std::move(file.get());
return fd;
}
bool FileCache::CloseFile(lldb::user_id_t fd, Status &error) {
if (fd == UINT64_MAX) {
error.SetErrorString("invalid file descriptor");
return false;
}
FDToFileMap::iterator pos = m_cache.find(fd);
if (pos == m_cache.end()) {
error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
return false;
}
FileUP &file_up = pos->second;
if (!file_up) {
error.SetErrorString("invalid host backing file");
return false;
}
error = file_up->Close();
m_cache.erase(pos);
return error.Success();
}
uint64_t FileCache::WriteFile(lldb::user_id_t fd, uint64_t offset,
const void *src, uint64_t src_len,
Status &error) {
if (fd == UINT64_MAX) {
error.SetErrorString("invalid file descriptor");
return UINT64_MAX;
}
FDToFileMap::iterator pos = m_cache.find(fd);
if (pos == m_cache.end()) {
error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
return false;
}
FileUP &file_up = pos->second;
if (!file_up) {
error.SetErrorString("invalid host backing file");
return UINT64_MAX;
}
if (static_cast<uint64_t>(file_up->SeekFromStart(offset, &error)) != offset ||
error.Fail())
return UINT64_MAX;
size_t bytes_written = src_len;
error = file_up->Write(src, bytes_written);
if (error.Fail())
return UINT64_MAX;
return bytes_written;
}
uint64_t FileCache::ReadFile(lldb::user_id_t fd, uint64_t offset, void *dst,
uint64_t dst_len, Status &error) {
if (fd == UINT64_MAX) {
error.SetErrorString("invalid file descriptor");
return UINT64_MAX;
}
FDToFileMap::iterator pos = m_cache.find(fd);
if (pos == m_cache.end()) {
error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
return false;
}
FileUP &file_up = pos->second;
if (!file_up) {
error.SetErrorString("invalid host backing file");
return UINT64_MAX;
}
if (static_cast<uint64_t>(file_up->SeekFromStart(offset, &error)) != offset ||
error.Fail())
return UINT64_MAX;
size_t bytes_read = dst_len;
error = file_up->Read(dst, bytes_read);
if (error.Fail())
return UINT64_MAX;
return bytes_read;
}