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Diffstat (limited to 'utils.h')
| -rw-r--r-- | utils.h | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/utils.h b/utils.h new file mode 100644 index 00000000..e4757832 --- /dev/null +++ b/utils.h @@ -0,0 +1,184 @@ +// Copyright (c) 2009 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__ +#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__ + +#include <set> +#include <string> +#include <vector> +#include "update_engine/action.h" +#include "update_engine/action_processor.h" + +namespace chromeos_update_engine { + +namespace utils { + +// Returns the entire contents of the file at path. Returns true on success. +bool ReadFile(const std::string& path, std::vector<char>* out); +bool ReadFileToString(const std::string& path, std::string* out); + +std::string ErrnoNumberAsString(int err); + +// Strips duplicate slashes, and optionally removes all trailing slashes. +// Does not compact /./ or /../. +std::string NormalizePath(const std::string& path, bool strip_trailing_slash); + +// Returns true if the file exists for sure. Returns false if it doesn't exist, +// or an error occurs. +bool FileExists(const char* path); + +// The last 6 chars of path must be XXXXXX. They will be randomly changed +// and a non-existent path will be returned. Intentionally makes a copy +// of the string passed in. +// NEVER CALL THIS FUNCTION UNLESS YOU ARE SURE +// THAT YOUR PROCESS WILL BE THE ONLY THING WRITING FILES IN THIS DIRECTORY. +std::string TempFilename(string path); + +// Deletes a directory and all its contents synchronously. Returns true +// on success. This may be called with a regular file--it will just unlink it. +// This WILL cross filesystem boundaries. +bool RecursiveUnlinkDir(const std::string& path); + +// Synchronously mount or unmount a filesystem. Return true on success. +// Mounts as ext3 with default options. +bool MountFilesystem(const string& device, const string& mountpoint); +bool UnmountFilesystem(const string& mountpoint); + +// Log a string in hex to LOG(INFO). Useful for debugging. +void HexDumpArray(const unsigned char* const arr, const size_t length); +inline void HexDumpString(const std::string& str) { + HexDumpArray(reinterpret_cast<const unsigned char*>(str.data()), str.size()); +} +inline void HexDumpVector(const std::vector<char>& vect) { + HexDumpArray(reinterpret_cast<const unsigned char*>(&vect[0]), vect.size()); +} + +extern const string kStatefulPartition; + +bool StringHasSuffix(const std::string& str, const std::string& suffix); +bool StringHasPrefix(const std::string& str, const std::string& prefix); + +template<typename KeyType, typename ValueType> +bool MapContainsKey(const std::map<KeyType, ValueType>& m, const KeyType& k) { + return m.find(k) != m.end(); +} + +template<typename ValueType> +std::set<ValueType> SetWithValue(const ValueType& value) { + std::set<ValueType> ret; + ret.insert(value); + return ret; +} + +// Returns the currently booted device. "/dev/sda1", for example. +// This will not interpret LABEL= or UUID=. You'll need to use findfs +// or something with equivalent funcionality to interpret those. +const std::string BootDevice(); + +} // namespace utils + +// Class to unmount FS when object goes out of scope +class ScopedFilesystemUnmounter { + public: + explicit ScopedFilesystemUnmounter(const std::string& mountpoint) + : mountpoint_(mountpoint) {} + ~ScopedFilesystemUnmounter() { + utils::UnmountFilesystem(mountpoint_); + } + private: + const std::string mountpoint_; +}; + +// Utility class to close a file descriptor +class ScopedFdCloser { + public: + explicit ScopedFdCloser(int* fd) : fd_(fd), should_close_(true) {} + void set_should_close(bool should_close) { should_close_ = should_close; } + ~ScopedFdCloser() { + if (!should_close_) + return; + if (fd_ && (*fd_ >= 0)) { + close(*fd_); + *fd_ = -1; + } + } + private: + int* fd_; + bool should_close_; +}; + +// A little object to call ActionComplete on the ActionProcessor when +// it's destructed. +class ScopedActionCompleter { + public: + explicit ScopedActionCompleter(ActionProcessor* processor, + AbstractAction* action) + : processor_(processor), + action_(action), + success_(false), + should_complete_(true) {} + ~ScopedActionCompleter() { + if (should_complete_) + processor_->ActionComplete(action_, success_); + } + void set_success(bool success) { + success_ = success; + } + void set_should_complete(bool should_complete) { + should_complete_ = should_complete; + } + private: + ActionProcessor* processor_; + AbstractAction* action_; + bool success_; + bool should_complete_; + DISALLOW_COPY_AND_ASSIGN(ScopedActionCompleter); +}; + +} // namespace chromeos_update_engine + +#define TEST_AND_RETURN_FALSE_ERRNO(_x) \ + do { \ + bool _success = (_x); \ + if (!_success) { \ + std::string _msg = \ + chromeos_update_engine::utils::ErrnoNumberAsString(errno); \ + LOG(ERROR) << #_x " failed: " << _msg; \ + return false; \ + } \ + } while (0) + +#define TEST_AND_RETURN_FALSE(_x) \ + do { \ + bool _success = (_x); \ + if (!_success) { \ + LOG(ERROR) << #_x " failed."; \ + return false; \ + } \ + } while (0) + +#define TEST_AND_RETURN_ERRNO(_x) \ + do { \ + bool _success = (_x); \ + if (!_success) { \ + std::string _msg = \ + chromeos_update_engine::utils::ErrnoNumberAsString(errno); \ + LOG(ERROR) << #_x " failed: " << _msg; \ + return; \ + } \ + } while (0) + +#define TEST_AND_RETURN(_x) \ + do { \ + bool _success = (_x); \ + if (!_success) { \ + LOG(ERROR) << #_x " failed."; \ + return; \ + } \ + } while (0) + + + +#endif // CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__ |