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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_FileUtils_h
#define mozilla_FileUtils_h
#include "nscore.h" // nullptr
#if defined(XP_UNIX)
# include <unistd.h>
#elif defined(XP_WIN)
# include <io.h>
#endif
#include "prio.h"
#include "prlink.h"
#include "mozilla/Scoped.h"
#include "nsIFile.h"
#include <errno.h>
#include <limits.h>
namespace mozilla {
#if defined(XP_WIN)
typedef void* filedesc_t;
typedef const wchar_t* pathstr_t;
#else
typedef int filedesc_t;
typedef const char* pathstr_t;
#endif
/**
* ScopedCloseFD is a RAII wrapper for POSIX file descriptors
*
* Instances |close()| their fds when they go out of scope.
*/
struct ScopedCloseFDTraits {
typedef int type;
static type empty() { return -1; }
static void release(type aFd) {
if (aFd != -1) {
close(aFd);
}
}
};
typedef Scoped<ScopedCloseFDTraits> ScopedClose;
#if defined(MOZILLA_INTERNAL_API)
/**
* AutoFDClose is a RAII wrapper for PRFileDesc.
*
* Instances |PR_Close| their fds when they go out of scope.
**/
struct ScopedClosePRFDTraits {
typedef PRFileDesc* type;
static type empty() { return nullptr; }
static void release(type aFd) {
if (aFd) {
PR_Close(aFd);
}
}
};
typedef Scoped<ScopedClosePRFDTraits> AutoFDClose;
/* RAII wrapper for FILE descriptors */
struct ScopedCloseFileTraits {
typedef FILE* type;
static type empty() { return nullptr; }
static void release(type aFile) {
if (aFile) {
fclose(aFile);
}
}
};
typedef Scoped<ScopedCloseFileTraits> ScopedCloseFile;
/**
* Fallocate efficiently and continuously allocates files via fallocate-type
* APIs. This is useful for avoiding fragmentation. On sucess the file be padded
* with zeros to grow to aLength.
*
* @param aFD file descriptor.
* @param aLength length of file to grow to.
* @return true on success.
*/
bool fallocate(PRFileDesc* aFD, int64_t aLength);
/**
* Use readahead to preload shared libraries into the file cache before loading.
* WARNING: This function should not be used without a telemetry field trial
* demonstrating a clear performance improvement!
*
* @param aFile nsIFile representing path to shared library
*/
void ReadAheadLib(nsIFile* aFile);
/**
* Use readahead to preload a file into the file cache before reading.
* WARNING: This function should not be used without a telemetry field trial
* demonstrating a clear performance improvement!
*
* @param aFile nsIFile representing path to shared library
* @param aOffset Offset into the file to begin preloading
* @param aCount Number of bytes to preload (SIZE_MAX implies file size)
* @param aOutFd Pointer to file descriptor. If specified, ReadAheadFile will
* return its internal, opened file descriptor instead of closing it.
*/
void ReadAheadFile(nsIFile* aFile, const size_t aOffset = 0,
const size_t aCount = SIZE_MAX,
filedesc_t* aOutFd = nullptr);
/*
* Wrappers for PR_GetLibraryName and PR_GetLibraryFilePathname.
*/
PathString GetLibraryName(pathstr_t aDirectory, const char* aLib);
PathString GetLibraryFilePathname(pathstr_t aName, PRFuncPtr aAddr);
#endif // MOZILLA_INTERNAL_API
/**
* Use readahead to preload shared libraries into the file cache before loading.
* WARNING: This function should not be used without a telemetry field trial
* demonstrating a clear performance improvement!
*
* @param aFilePath path to shared library
*/
void ReadAheadLib(pathstr_t aFilePath);
/**
* Use readahead to preload a file into the file cache before loading.
* WARNING: This function should not be used without a telemetry field trial
* demonstrating a clear performance improvement!
*
* @param aFilePath path to shared library
* @param aOffset Offset into the file to begin preloading
* @param aCount Number of bytes to preload (SIZE_MAX implies file size)
* @param aOutFd Pointer to file descriptor. If specified, ReadAheadFile will
* return its internal, opened file descriptor instead of closing it.
*/
void ReadAheadFile(pathstr_t aFilePath, const size_t aOffset = 0,
const size_t aCount = SIZE_MAX,
filedesc_t* aOutFd = nullptr);
/**
* Use readahead to preload a file into the file cache before reading.
* When this function exits, the file pointer is guaranteed to be in the same
* position it was in before this function was called.
* WARNING: This function should not be used without a telemetry field trial
* demonstrating a clear performance improvement!
*
* @param aFd file descriptor opened for read access
* (on Windows, file must be opened with FILE_FLAG_SEQUENTIAL_SCAN)
* @param aOffset Offset into the file to begin preloading
* @param aCount Number of bytes to preload (SIZE_MAX implies file size)
*/
void ReadAhead(filedesc_t aFd, const size_t aOffset = 0,
const size_t aCount = SIZE_MAX);
} // namespace mozilla
#endif