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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
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Add m-esr52 at 52.6.0
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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 "SeekableZStream.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:
+ /**
+ * Ensures the availability of the memory pages for the page(s) containing
+ * the given address. Returns whether the pages were successfully made
+ * available.
+ */
+ virtual bool ensure(const void *addr) { return true; }
+
+ /**
+ * Indicate to a Mappable instance that no further mmap is going to happen.
+ */
+ virtual void finalize() = 0;
+
+ /**
+ * Shows some stats about the Mappable instance.
+ * Meant for MappableSeekableZStream only.
+ * As Mappables don't keep track of what they are instanciated for, the name
+ * argument is used to make the stats logging useful to the reader. The when
+ * argument is to be used by the caller to give an identifier of the when
+ * the stats call is made.
+ */
+ virtual void stats(const char *when, const char *name) const { }
+
+ /**
+ * 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:
+ 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 */
+ zxx_stream zStream;
+};
+
+/**
+ * Mappable implementation for seekable zStreams.
+ * Inflates the mapped bits in a temporary buffer, on demand.
+ */
+class MappableSeekableZStream: public Mappable
+{
+public:
+ ~MappableSeekableZStream();
+
+ /**
+ * Create a MappableSeekableZStream 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 MappableSeekableZStream 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 munmap(void *addr, size_t length);
+ virtual void finalize();
+ virtual bool ensure(const void *addr);
+ virtual void stats(const char *when, const char *name) const;
+ virtual size_t GetLength() const;
+
+ virtual Kind GetKind() const { return MAPPABLE_SEEKABLE_ZSTREAM; };
+private:
+ MappableSeekableZStream(Zip *zip);
+
+ /* Zip reference */
+ RefPtr<Zip> zip;
+
+ /* Decompression buffer */
+ mozilla::UniquePtr<_MappableBuffer> buffer;
+
+ /* Seekable ZStream */
+ SeekableZStream zStream;
+
+ /* Keep track of mappings performed with MappableSeekableZStream::mmap so
+ * that they can be realized by MappableSeekableZStream::ensure.
+ * Values stored in the struct are those passed to mmap */
+ struct LazyMap
+ {
+ const void *addr;
+ size_t length;
+ int prot;
+ off_t offset;
+
+ /* Returns addr + length, as a pointer */
+ const void *end() const {
+ return reinterpret_cast<const void *>
+ (reinterpret_cast<const unsigned char *>(addr) + length);
+ }
+
+ /* Returns offset + length */
+ off_t endOffset() const {
+ return offset + length;
+ }
+
+ /* Returns the offset corresponding to the given address */
+ off_t offsetOf(const void *ptr) const {
+ return reinterpret_cast<uintptr_t>(ptr)
+ - reinterpret_cast<uintptr_t>(addr) + offset;
+ }
+
+ /* Returns whether the given address is in the LazyMap range */
+ bool Contains(const void *ptr) const {
+ return (ptr >= addr) && (ptr < end());
+ }
+ };
+
+ /* List of all mappings */
+ std::vector<LazyMap> lazyMaps;
+
+ /* Array keeping track of which chunks have already been decompressed.
+ * Each value is the number of pages decompressed for the given chunk. */
+ mozilla::UniquePtr<unsigned char[]> chunkAvail;
+
+ /* Number of chunks that have already been decompressed. */
+ mozilla::Atomic<size_t> chunkAvailNum;
+
+ /* Mutex protecting decompression */
+ pthread_mutex_t mutex;
+};
+
+#endif /* Mappable_h */