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/* 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 Mappable_h
#define Mappable_h
#include "Zip.h"
#include "mozilla/RefPtr.h"
#include "mozilla/UniquePtr.h"
#include "zlib.h"
/**
* Abstract class to handle mmap()ing from various kind of entities, such as
* plain files or Zip entries. The virtual members are meant to act as the
* equivalent system functions, except mapped memory is always MAP_PRIVATE,
* even though a given implementation may use something different internally.
*/
class Mappable : public mozilla::RefCounted<Mappable> {
public:
MOZ_DECLARE_REFCOUNTED_TYPENAME(Mappable)
virtual ~Mappable() {}
virtual MemoryRange mmap(const void* addr, size_t length, int prot, int flags,
off_t offset) = 0;
enum Kind {
MAPPABLE_FILE,
MAPPABLE_EXTRACT_FILE,
MAPPABLE_DEFLATE,
MAPPABLE_SEEKABLE_ZSTREAM
};
virtual Kind GetKind() const = 0;
private:
virtual void munmap(void* addr, size_t length) { ::munmap(addr, length); }
/* Limit use of Mappable::munmap to classes that keep track of the address
* and size of the mapping. This allows to ignore ::munmap return value. */
friend class Mappable1stPagePtr;
friend class LibHandle;
public:
/**
* Indicate to a Mappable instance that no further mmap is going to happen.
*/
virtual void finalize() = 0;
/**
* Returns the maximum length that can be mapped from this Mappable for
* offset = 0.
*/
virtual size_t GetLength() const = 0;
};
/**
* Mappable implementation for plain files
*/
class MappableFile : public Mappable {
public:
~MappableFile() {}
/**
* Create a MappableFile instance for the given file path.
*/
static Mappable* Create(const char* path);
/* Inherited from Mappable */
virtual MemoryRange mmap(const void* addr, size_t length, int prot, int flags,
off_t offset);
virtual void finalize();
virtual size_t GetLength() const;
virtual Kind GetKind() const { return MAPPABLE_FILE; };
protected:
explicit MappableFile(int fd) : fd(fd) {}
private:
/* File descriptor */
AutoCloseFD fd;
};
/**
* Mappable implementation for deflated stream in a Zip archive
* Inflates the complete stream into a cache file.
*/
class MappableExtractFile : public MappableFile {
public:
~MappableExtractFile() = default;
/**
* Create a MappableExtractFile instance for the given Zip stream. The name
* argument is used to create the cache file in the cache directory.
*/
static Mappable* Create(const char* name, Zip* zip, Zip::Stream* stream);
/* Override finalize from MappableFile */
virtual void finalize() {}
virtual Kind GetKind() const { return MAPPABLE_EXTRACT_FILE; };
private:
/**
* AutoUnlinkFile keeps track of a file name and removes (unlinks) the file
* when the instance is destroyed.
*/
struct UnlinkFile {
void operator()(char* value) {
unlink(value);
delete[] value;
}
};
typedef mozilla::UniquePtr<char[], UnlinkFile> AutoUnlinkFile;
MappableExtractFile(int fd, const char* path)
: MappableFile(fd), path(path) {}
/* Extracted file path */
mozilla::UniquePtr<const char[]> path;
};
class _MappableBuffer;
/**
* Mappable implementation for deflated stream in a Zip archive.
* Inflates the mapped bits in a temporary buffer.
*/
class MappableDeflate : public Mappable {
public:
~MappableDeflate();
/**
* Create a MappableDeflate instance for the given Zip stream. The name
* argument is used for an appropriately named temporary file, and the Zip
* instance is given for the MappableDeflate to keep a reference of it.
*/
static Mappable* Create(const char* name, Zip* zip, Zip::Stream* stream);
/* Inherited from Mappable */
virtual MemoryRange mmap(const void* addr, size_t length, int prot, int flags,
off_t offset);
virtual void finalize();
virtual size_t GetLength() const;
virtual Kind GetKind() const { return MAPPABLE_DEFLATE; };
private:
MappableDeflate(_MappableBuffer* buf, Zip* zip, Zip::Stream* stream);
/* Zip reference */
RefPtr<Zip> zip;
/* Decompression buffer */
mozilla::UniquePtr<_MappableBuffer> buffer;
/* Zlib data */
z_stream zStream;
};
#endif /* Mappable_h */