michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef Mappable_h
michael@0: #define Mappable_h
michael@0: 
michael@0: #include <sys/types.h>
michael@0: #include <pthread.h>
michael@0: #include "Zip.h"
michael@0: #include "SeekableZStream.h"
michael@0: #include "mozilla/RefPtr.h"
michael@0: #include "mozilla/Scoped.h"
michael@0: #include "zlib.h"
michael@0: 
michael@0: /**
michael@0:  * Abstract class to handle mmap()ing from various kind of entities, such as
michael@0:  * plain files or Zip entries. The virtual members are meant to act as the
michael@0:  * equivalent system functions, except mapped memory is always MAP_PRIVATE,
michael@0:  * even though a given implementation may use something different internally.
michael@0:  */
michael@0: class Mappable: public mozilla::RefCounted<Mappable>
michael@0: {
michael@0: public:
michael@0:   MOZ_DECLARE_REFCOUNTED_TYPENAME(Mappable)
michael@0:   virtual ~Mappable() { }
michael@0: 
michael@0:   virtual MemoryRange mmap(const void *addr, size_t length, int prot, int flags,
michael@0:                            off_t offset) = 0;
michael@0: 
michael@0:   enum Kind {
michael@0:     MAPPABLE_FILE,
michael@0:     MAPPABLE_EXTRACT_FILE,
michael@0:     MAPPABLE_DEFLATE,
michael@0:     MAPPABLE_SEEKABLE_ZSTREAM
michael@0:   };
michael@0: 
michael@0:   virtual Kind GetKind() const = 0;
michael@0: 
michael@0: private:
michael@0:   virtual void munmap(void *addr, size_t length) {
michael@0:     ::munmap(addr, length);
michael@0:   }
michael@0:   /* Limit use of Mappable::munmap to classes that keep track of the address
michael@0:    * and size of the mapping. This allows to ignore ::munmap return value. */
michael@0:   friend class Mappable1stPagePtr;
michael@0:   friend class LibHandle;
michael@0: 
michael@0: public:
michael@0:   /**
michael@0:    * Ensures the availability of the memory pages for the page(s) containing
michael@0:    * the given address. Returns whether the pages were successfully made
michael@0:    * available.
michael@0:    */
michael@0:   virtual bool ensure(const void *addr) { return true; }
michael@0: 
michael@0:   /**
michael@0:    * Indicate to a Mappable instance that no further mmap is going to happen.
michael@0:    */
michael@0:   virtual void finalize() = 0;
michael@0: 
michael@0:   /**
michael@0:    * Shows some stats about the Mappable instance.
michael@0:    * Meant for MappableSeekableZStream only.
michael@0:    * As Mappables don't keep track of what they are instanciated for, the name
michael@0:    * argument is used to make the stats logging useful to the reader. The when
michael@0:    * argument is to be used by the caller to give an identifier of the when
michael@0:    * the stats call is made.
michael@0:    */
michael@0:   virtual void stats(const char *when, const char *name) const { }
michael@0: 
michael@0:   /**
michael@0:    * Returns the maximum length that can be mapped from this Mappable for
michael@0:    * offset = 0.
michael@0:    */
michael@0:   virtual size_t GetLength() const = 0;
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Mappable implementation for plain files
michael@0:  */
michael@0: class MappableFile: public Mappable
michael@0: {
michael@0: public:
michael@0:   ~MappableFile() { }
michael@0: 
michael@0:   /**
michael@0:    * Create a MappableFile instance for the given file path.
michael@0:    */
michael@0:   static Mappable *Create(const char *path);
michael@0: 
michael@0:   /* Inherited from Mappable */
michael@0:   virtual MemoryRange mmap(const void *addr, size_t length, int prot, int flags, off_t offset);
michael@0:   virtual void finalize();
michael@0:   virtual size_t GetLength() const;
michael@0: 
michael@0:   virtual Kind GetKind() const { return MAPPABLE_FILE; };
michael@0: protected:
michael@0:   MappableFile(int fd): fd(fd) { }
michael@0: 
michael@0: private:
michael@0:   /* File descriptor */
michael@0:   AutoCloseFD fd;
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Mappable implementation for deflated stream in a Zip archive
michael@0:  * Inflates the complete stream into a cache file.
michael@0:  */
michael@0: class MappableExtractFile: public MappableFile
michael@0: {
michael@0: public:
michael@0:   ~MappableExtractFile();
michael@0: 
michael@0:   /**
michael@0:    * Create a MappableExtractFile instance for the given Zip stream. The name
michael@0:    * argument is used to create the cache file in the cache directory.
michael@0:    */
michael@0:   static Mappable *Create(const char *name, Zip *zip, Zip::Stream *stream);
michael@0: 
michael@0:   /* Override finalize from MappableFile */
michael@0:   virtual void finalize() {}
michael@0: 
michael@0:   virtual Kind GetKind() const { return MAPPABLE_EXTRACT_FILE; };
michael@0: private:
michael@0:   MappableExtractFile(int fd, char *path)
michael@0:   : MappableFile(fd), path(path), pid(getpid()) { }
michael@0: 
michael@0:   /**
michael@0:    * AutoUnlinkFile keeps track or a file name and removes (unlinks) the file
michael@0:    * when the instance is destroyed.
michael@0:    */
michael@0:   struct AutoUnlinkFileTraits: public mozilla::ScopedDeleteArrayTraits<char>
michael@0:   {
michael@0:     static void release(char *value)
michael@0:     {
michael@0:       if (!value)
michael@0:         return;
michael@0:       unlink(value);
michael@0:       mozilla::ScopedDeleteArrayTraits<char>::release(value);
michael@0:     }
michael@0:   };
michael@0:   typedef mozilla::Scoped<AutoUnlinkFileTraits> AutoUnlinkFile;
michael@0: 
michael@0:   /* Extracted file */
michael@0:   AutoUnlinkFile path;
michael@0: 
michael@0:   /* Id of the process that initialized the instance */
michael@0:   pid_t pid;
michael@0: };
michael@0: 
michael@0: class _MappableBuffer;
michael@0: 
michael@0: /**
michael@0:  * Mappable implementation for deflated stream in a Zip archive.
michael@0:  * Inflates the mapped bits in a temporary buffer. 
michael@0:  */
michael@0: class MappableDeflate: public Mappable
michael@0: {
michael@0: public:
michael@0:   ~MappableDeflate();
michael@0: 
michael@0:   /**
michael@0:    * Create a MappableDeflate instance for the given Zip stream. The name
michael@0:    * argument is used for an appropriately named temporary file, and the Zip
michael@0:    * instance is given for the MappableDeflate to keep a reference of it.
michael@0:    */
michael@0:   static Mappable *Create(const char *name, Zip *zip, Zip::Stream *stream);
michael@0: 
michael@0:   /* Inherited from Mappable */
michael@0:   virtual MemoryRange mmap(const void *addr, size_t length, int prot, int flags, off_t offset);
michael@0:   virtual void finalize();
michael@0:   virtual size_t GetLength() const;
michael@0: 
michael@0:   virtual Kind GetKind() const { return MAPPABLE_DEFLATE; };
michael@0: private:
michael@0:   MappableDeflate(_MappableBuffer *buf, Zip *zip, Zip::Stream *stream);
michael@0: 
michael@0:   /* Zip reference */
michael@0:   mozilla::RefPtr<Zip> zip;
michael@0: 
michael@0:   /* Decompression buffer */
michael@0:   mozilla::ScopedDeletePtr<_MappableBuffer> buffer;
michael@0: 
michael@0:   /* Zlib data */
michael@0:   z_stream zStream;
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Mappable implementation for seekable zStreams.
michael@0:  * Inflates the mapped bits in a temporary buffer, on demand.
michael@0:  */
michael@0: class MappableSeekableZStream: public Mappable
michael@0: {
michael@0: public:
michael@0:   ~MappableSeekableZStream();
michael@0: 
michael@0:   /**
michael@0:    * Create a MappableSeekableZStream instance for the given Zip stream. The
michael@0:    * name argument is used for an appropriately named temporary file, and the
michael@0:    * Zip instance is given for the MappableSeekableZStream to keep a reference
michael@0:    * of it.
michael@0:    */
michael@0:   static Mappable *Create(const char *name, Zip *zip,
michael@0:                                          Zip::Stream *stream);
michael@0: 
michael@0:   /* Inherited from Mappable */
michael@0:   virtual MemoryRange mmap(const void *addr, size_t length, int prot, int flags, off_t offset);
michael@0:   virtual void munmap(void *addr, size_t length);
michael@0:   virtual void finalize();
michael@0:   virtual bool ensure(const void *addr);
michael@0:   virtual void stats(const char *when, const char *name) const;
michael@0:   virtual size_t GetLength() const;
michael@0: 
michael@0:   virtual Kind GetKind() const { return MAPPABLE_SEEKABLE_ZSTREAM; };
michael@0: private:
michael@0:   MappableSeekableZStream(Zip *zip);
michael@0: 
michael@0:   /* Zip reference */
michael@0:   mozilla::RefPtr<Zip> zip;
michael@0: 
michael@0:   /* Decompression buffer */
michael@0:   mozilla::ScopedDeletePtr<_MappableBuffer> buffer;
michael@0: 
michael@0:   /* Seekable ZStream */
michael@0:   SeekableZStream zStream;
michael@0: 
michael@0:   /* Keep track of mappings performed with MappableSeekableZStream::mmap so
michael@0:    * that they can be realized by MappableSeekableZStream::ensure.
michael@0:    * Values stored in the struct are those passed to mmap */
michael@0:   struct LazyMap
michael@0:   {
michael@0:     const void *addr;
michael@0:     size_t length;
michael@0:     int prot;
michael@0:     off_t offset;
michael@0: 
michael@0:     /* Returns addr + length, as a pointer */
michael@0:     const void *end() const {
michael@0:       return reinterpret_cast<const void *>
michael@0:              (reinterpret_cast<const unsigned char *>(addr) + length);
michael@0:     }
michael@0: 
michael@0:     /* Returns offset + length */
michael@0:     const off_t endOffset() const {
michael@0:       return offset + length;
michael@0:     }
michael@0: 
michael@0:     /* Returns the offset corresponding to the given address */
michael@0:     const off_t offsetOf(const void *ptr) const {
michael@0:       return reinterpret_cast<uintptr_t>(ptr)
michael@0:              - reinterpret_cast<uintptr_t>(addr) + offset;
michael@0:     }
michael@0: 
michael@0:     /* Returns whether the given address is in the LazyMap range */
michael@0:     const bool Contains(const void *ptr) const {
michael@0:       return (ptr >= addr) && (ptr < end());
michael@0:     }
michael@0:   };
michael@0: 
michael@0:   /* List of all mappings */
michael@0:   std::vector<LazyMap> lazyMaps;
michael@0: 
michael@0:   /* Array keeping track of which chunks have already been decompressed.
michael@0:    * Each value is the number of pages decompressed for the given chunk. */
michael@0:   mozilla::ScopedDeleteArray<unsigned char> chunkAvail;
michael@0: 
michael@0:   /* Number of chunks that have already been decompressed. */
michael@0:   mozilla::Atomic<size_t> chunkAvailNum;
michael@0: 
michael@0:   /* Mutex protecting decompression */
michael@0:   pthread_mutex_t mutex;
michael@0: };
michael@0: 
michael@0: #endif /* Mappable_h */