Adds a modified copy of talk/base to webrtc/base. It is the first step in
migrating talk/base to webrtc/base.
BUG=N/A
R=niklas.enbom@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/17479005
git-svn-id: http://webrtc.googlecode.com/svn/trunk@6129 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/base/stream.h b/webrtc/base/stream.h
new file mode 100644
index 0000000..00ded37
--- /dev/null
+++ b/webrtc/base/stream.h
@@ -0,0 +1,820 @@
+/*
+ * Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_BASE_STREAM_H_
+#define WEBRTC_BASE_STREAM_H_
+
+#include <stdio.h>
+
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/messagehandler.h"
+#include "webrtc/base/messagequeue.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/sigslot.h"
+
+namespace rtc {
+
+///////////////////////////////////////////////////////////////////////////////
+// StreamInterface is a generic asynchronous stream interface, supporting read,
+// write, and close operations, and asynchronous signalling of state changes.
+// The interface is designed with file, memory, and socket implementations in
+// mind. Some implementations offer extended operations, such as seeking.
+///////////////////////////////////////////////////////////////////////////////
+
+// The following enumerations are declared outside of the StreamInterface
+// class for brevity in use.
+
+// The SS_OPENING state indicates that the stream will signal open or closed
+// in the future.
+enum StreamState { SS_CLOSED, SS_OPENING, SS_OPEN };
+
+// Stream read/write methods return this value to indicate various success
+// and failure conditions described below.
+enum StreamResult { SR_ERROR, SR_SUCCESS, SR_BLOCK, SR_EOS };
+
+// StreamEvents are used to asynchronously signal state transitionss. The flags
+// may be combined.
+// SE_OPEN: The stream has transitioned to the SS_OPEN state
+// SE_CLOSE: The stream has transitioned to the SS_CLOSED state
+// SE_READ: Data is available, so Read is likely to not return SR_BLOCK
+// SE_WRITE: Data can be written, so Write is likely to not return SR_BLOCK
+enum StreamEvent { SE_OPEN = 1, SE_READ = 2, SE_WRITE = 4, SE_CLOSE = 8 };
+
+class Thread;
+
+struct StreamEventData : public MessageData {
+ int events, error;
+ StreamEventData(int ev, int er) : events(ev), error(er) { }
+};
+
+class StreamInterface : public MessageHandler {
+ public:
+ enum {
+ MSG_POST_EVENT = 0xF1F1, MSG_MAX = MSG_POST_EVENT
+ };
+
+ virtual ~StreamInterface();
+
+ virtual StreamState GetState() const = 0;
+
+ // Read attempts to fill buffer of size buffer_len. Write attempts to send
+ // data_len bytes stored in data. The variables read and write are set only
+ // on SR_SUCCESS (see below). Likewise, error is only set on SR_ERROR.
+ // Read and Write return a value indicating:
+ // SR_ERROR: an error occurred, which is returned in a non-null error
+ // argument. Interpretation of the error requires knowledge of the
+ // stream's concrete type, which limits its usefulness.
+ // SR_SUCCESS: some number of bytes were successfully written, which is
+ // returned in a non-null read/write argument.
+ // SR_BLOCK: the stream is in non-blocking mode, and the operation would
+ // block, or the stream is in SS_OPENING state.
+ // SR_EOS: the end-of-stream has been reached, or the stream is in the
+ // SS_CLOSED state.
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error) = 0;
+ virtual StreamResult Write(const void* data, size_t data_len,
+ size_t* written, int* error) = 0;
+ // Attempt to transition to the SS_CLOSED state. SE_CLOSE will not be
+ // signalled as a result of this call.
+ virtual void Close() = 0;
+
+ // Streams may signal one or more StreamEvents to indicate state changes.
+ // The first argument identifies the stream on which the state change occured.
+ // The second argument is a bit-wise combination of StreamEvents.
+ // If SE_CLOSE is signalled, then the third argument is the associated error
+ // code. Otherwise, the value is undefined.
+ // Note: Not all streams will support asynchronous event signalling. However,
+ // SS_OPENING and SR_BLOCK returned from stream member functions imply that
+ // certain events will be raised in the future.
+ sigslot::signal3<StreamInterface*, int, int> SignalEvent;
+
+ // Like calling SignalEvent, but posts a message to the specified thread,
+ // which will call SignalEvent. This helps unroll the stack and prevent
+ // re-entrancy.
+ void PostEvent(Thread* t, int events, int err);
+ // Like the aforementioned method, but posts to the current thread.
+ void PostEvent(int events, int err);
+
+ //
+ // OPTIONAL OPERATIONS
+ //
+ // Not all implementations will support the following operations. In general,
+ // a stream will only support an operation if it reasonably efficient to do
+ // so. For example, while a socket could buffer incoming data to support
+ // seeking, it will not do so. Instead, a buffering stream adapter should
+ // be used.
+ //
+ // Even though several of these operations are related, you should
+ // always use whichever operation is most relevant. For example, you may
+ // be tempted to use GetSize() and GetPosition() to deduce the result of
+ // GetAvailable(). However, a stream which is read-once may support the
+ // latter operation but not the former.
+ //
+
+ // The following four methods are used to avoid copying data multiple times.
+
+ // GetReadData returns a pointer to a buffer which is owned by the stream.
+ // The buffer contains data_len bytes. NULL is returned if no data is
+ // available, or if the method fails. If the caller processes the data, it
+ // must call ConsumeReadData with the number of processed bytes. GetReadData
+ // does not require a matching call to ConsumeReadData if the data is not
+ // processed. Read and ConsumeReadData invalidate the buffer returned by
+ // GetReadData.
+ virtual const void* GetReadData(size_t* data_len) { return NULL; }
+ virtual void ConsumeReadData(size_t used) {}
+
+ // GetWriteBuffer returns a pointer to a buffer which is owned by the stream.
+ // The buffer has a capacity of buf_len bytes. NULL is returned if there is
+ // no buffer available, or if the method fails. The call may write data to
+ // the buffer, and then call ConsumeWriteBuffer with the number of bytes
+ // written. GetWriteBuffer does not require a matching call to
+ // ConsumeWriteData if no data is written. Write, ForceWrite, and
+ // ConsumeWriteData invalidate the buffer returned by GetWriteBuffer.
+ // TODO: Allow the caller to specify a minimum buffer size. If the specified
+ // amount of buffer is not yet available, return NULL and Signal SE_WRITE
+ // when it is available. If the requested amount is too large, return an
+ // error.
+ virtual void* GetWriteBuffer(size_t* buf_len) { return NULL; }
+ virtual void ConsumeWriteBuffer(size_t used) {}
+
+ // Write data_len bytes found in data, circumventing any throttling which
+ // would could cause SR_BLOCK to be returned. Returns true if all the data
+ // was written. Otherwise, the method is unsupported, or an unrecoverable
+ // error occurred, and the error value is set. This method should be used
+ // sparingly to write critical data which should not be throttled. A stream
+ // which cannot circumvent its blocking constraints should not implement this
+ // method.
+ // NOTE: This interface is being considered experimentally at the moment. It
+ // would be used by JUDP and BandwidthStream as a way to circumvent certain
+ // soft limits in writing.
+ //virtual bool ForceWrite(const void* data, size_t data_len, int* error) {
+ // if (error) *error = -1;
+ // return false;
+ //}
+
+ // Seek to a byte offset from the beginning of the stream. Returns false if
+ // the stream does not support seeking, or cannot seek to the specified
+ // position.
+ virtual bool SetPosition(size_t position) { return false; }
+
+ // Get the byte offset of the current position from the start of the stream.
+ // Returns false if the position is not known.
+ virtual bool GetPosition(size_t* position) const { return false; }
+
+ // Get the byte length of the entire stream. Returns false if the length
+ // is not known.
+ virtual bool GetSize(size_t* size) const { return false; }
+
+ // Return the number of Read()-able bytes remaining before end-of-stream.
+ // Returns false if not known.
+ virtual bool GetAvailable(size_t* size) const { return false; }
+
+ // Return the number of Write()-able bytes remaining before end-of-stream.
+ // Returns false if not known.
+ virtual bool GetWriteRemaining(size_t* size) const { return false; }
+
+ // Return true if flush is successful.
+ virtual bool Flush() { return false; }
+
+ // Communicates the amount of data which will be written to the stream. The
+ // stream may choose to preallocate memory to accomodate this data. The
+ // stream may return false to indicate that there is not enough room (ie,
+ // Write will return SR_EOS/SR_ERROR at some point). Note that calling this
+ // function should not affect the existing state of data in the stream.
+ virtual bool ReserveSize(size_t size) { return true; }
+
+ //
+ // CONVENIENCE METHODS
+ //
+ // These methods are implemented in terms of other methods, for convenience.
+ //
+
+ // Seek to the start of the stream.
+ inline bool Rewind() { return SetPosition(0); }
+
+ // WriteAll is a helper function which repeatedly calls Write until all the
+ // data is written, or something other than SR_SUCCESS is returned. Note that
+ // unlike Write, the argument 'written' is always set, and may be non-zero
+ // on results other than SR_SUCCESS. The remaining arguments have the
+ // same semantics as Write.
+ StreamResult WriteAll(const void* data, size_t data_len,
+ size_t* written, int* error);
+
+ // Similar to ReadAll. Calls Read until buffer_len bytes have been read, or
+ // until a non-SR_SUCCESS result is returned. 'read' is always set.
+ StreamResult ReadAll(void* buffer, size_t buffer_len,
+ size_t* read, int* error);
+
+ // ReadLine is a helper function which repeatedly calls Read until it hits
+ // the end-of-line character, or something other than SR_SUCCESS.
+ // TODO: this is too inefficient to keep here. Break this out into a buffered
+ // readline object or adapter
+ StreamResult ReadLine(std::string* line);
+
+ protected:
+ StreamInterface();
+
+ // MessageHandler Interface
+ virtual void OnMessage(Message* msg);
+
+ private:
+ DISALLOW_EVIL_CONSTRUCTORS(StreamInterface);
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// StreamAdapterInterface is a convenient base-class for adapting a stream.
+// By default, all operations are pass-through. Override the methods that you
+// require adaptation. Streams should really be upgraded to reference-counted.
+// In the meantime, use the owned flag to indicate whether the adapter should
+// own the adapted stream.
+///////////////////////////////////////////////////////////////////////////////
+
+class StreamAdapterInterface : public StreamInterface,
+ public sigslot::has_slots<> {
+ public:
+ explicit StreamAdapterInterface(StreamInterface* stream, bool owned = true);
+
+ // Core Stream Interface
+ virtual StreamState GetState() const {
+ return stream_->GetState();
+ }
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error) {
+ return stream_->Read(buffer, buffer_len, read, error);
+ }
+ virtual StreamResult Write(const void* data, size_t data_len,
+ size_t* written, int* error) {
+ return stream_->Write(data, data_len, written, error);
+ }
+ virtual void Close() {
+ stream_->Close();
+ }
+
+ // Optional Stream Interface
+ /* Note: Many stream adapters were implemented prior to this Read/Write
+ interface. Therefore, a simple pass through of data in those cases may
+ be broken. At a later time, we should do a once-over pass of all
+ adapters, and make them compliant with these interfaces, after which this
+ code can be uncommented.
+ virtual const void* GetReadData(size_t* data_len) {
+ return stream_->GetReadData(data_len);
+ }
+ virtual void ConsumeReadData(size_t used) {
+ stream_->ConsumeReadData(used);
+ }
+
+ virtual void* GetWriteBuffer(size_t* buf_len) {
+ return stream_->GetWriteBuffer(buf_len);
+ }
+ virtual void ConsumeWriteBuffer(size_t used) {
+ stream_->ConsumeWriteBuffer(used);
+ }
+ */
+
+ /* Note: This interface is currently undergoing evaluation.
+ virtual bool ForceWrite(const void* data, size_t data_len, int* error) {
+ return stream_->ForceWrite(data, data_len, error);
+ }
+ */
+
+ virtual bool SetPosition(size_t position) {
+ return stream_->SetPosition(position);
+ }
+ virtual bool GetPosition(size_t* position) const {
+ return stream_->GetPosition(position);
+ }
+ virtual bool GetSize(size_t* size) const {
+ return stream_->GetSize(size);
+ }
+ virtual bool GetAvailable(size_t* size) const {
+ return stream_->GetAvailable(size);
+ }
+ virtual bool GetWriteRemaining(size_t* size) const {
+ return stream_->GetWriteRemaining(size);
+ }
+ virtual bool ReserveSize(size_t size) {
+ return stream_->ReserveSize(size);
+ }
+ virtual bool Flush() {
+ return stream_->Flush();
+ }
+
+ void Attach(StreamInterface* stream, bool owned = true);
+ StreamInterface* Detach();
+
+ protected:
+ virtual ~StreamAdapterInterface();
+
+ // Note that the adapter presents itself as the origin of the stream events,
+ // since users of the adapter may not recognize the adapted object.
+ virtual void OnEvent(StreamInterface* stream, int events, int err) {
+ SignalEvent(this, events, err);
+ }
+ StreamInterface* stream() { return stream_; }
+
+ private:
+ StreamInterface* stream_;
+ bool owned_;
+ DISALLOW_EVIL_CONSTRUCTORS(StreamAdapterInterface);
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// StreamTap is a non-modifying, pass-through adapter, which copies all data
+// in either direction to the tap. Note that errors or blocking on writing to
+// the tap will prevent further tap writes from occurring.
+///////////////////////////////////////////////////////////////////////////////
+
+class StreamTap : public StreamAdapterInterface {
+ public:
+ explicit StreamTap(StreamInterface* stream, StreamInterface* tap);
+
+ void AttachTap(StreamInterface* tap);
+ StreamInterface* DetachTap();
+ StreamResult GetTapResult(int* error);
+
+ // StreamAdapterInterface Interface
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error);
+ virtual StreamResult Write(const void* data, size_t data_len,
+ size_t* written, int* error);
+
+ private:
+ scoped_ptr<StreamInterface> tap_;
+ StreamResult tap_result_;
+ int tap_error_;
+ DISALLOW_EVIL_CONSTRUCTORS(StreamTap);
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// StreamSegment adapts a read stream, to expose a subset of the adapted
+// stream's data. This is useful for cases where a stream contains multiple
+// documents concatenated together. StreamSegment can expose a subset of
+// the data as an independent stream, including support for rewinding and
+// seeking.
+///////////////////////////////////////////////////////////////////////////////
+
+class StreamSegment : public StreamAdapterInterface {
+ public:
+ // The current position of the adapted stream becomes the beginning of the
+ // segment. If a length is specified, it bounds the length of the segment.
+ explicit StreamSegment(StreamInterface* stream);
+ explicit StreamSegment(StreamInterface* stream, size_t length);
+
+ // StreamAdapterInterface Interface
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error);
+ virtual bool SetPosition(size_t position);
+ virtual bool GetPosition(size_t* position) const;
+ virtual bool GetSize(size_t* size) const;
+ virtual bool GetAvailable(size_t* size) const;
+
+ private:
+ size_t start_, pos_, length_;
+ DISALLOW_EVIL_CONSTRUCTORS(StreamSegment);
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// NullStream gives errors on read, and silently discards all written data.
+///////////////////////////////////////////////////////////////////////////////
+
+class NullStream : public StreamInterface {
+ public:
+ NullStream();
+ virtual ~NullStream();
+
+ // StreamInterface Interface
+ virtual StreamState GetState() const;
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error);
+ virtual StreamResult Write(const void* data, size_t data_len,
+ size_t* written, int* error);
+ virtual void Close();
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// FileStream is a simple implementation of a StreamInterface, which does not
+// support asynchronous notification.
+///////////////////////////////////////////////////////////////////////////////
+
+class FileStream : public StreamInterface {
+ public:
+ FileStream();
+ virtual ~FileStream();
+
+ // The semantics of filename and mode are the same as stdio's fopen
+ virtual bool Open(const std::string& filename, const char* mode, int* error);
+ virtual bool OpenShare(const std::string& filename, const char* mode,
+ int shflag, int* error);
+
+ // By default, reads and writes are buffered for efficiency. Disabling
+ // buffering causes writes to block until the bytes on disk are updated.
+ virtual bool DisableBuffering();
+
+ virtual StreamState GetState() const;
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error);
+ virtual StreamResult Write(const void* data, size_t data_len,
+ size_t* written, int* error);
+ virtual void Close();
+ virtual bool SetPosition(size_t position);
+ virtual bool GetPosition(size_t* position) const;
+ virtual bool GetSize(size_t* size) const;
+ virtual bool GetAvailable(size_t* size) const;
+ virtual bool ReserveSize(size_t size);
+
+ virtual bool Flush();
+
+#if defined(WEBRTC_POSIX) && !defined(__native_client__)
+ // Tries to aquire an exclusive lock on the file.
+ // Use OpenShare(...) on win32 to get similar functionality.
+ bool TryLock();
+ bool Unlock();
+#endif
+
+ // Note: Deprecated in favor of Filesystem::GetFileSize().
+ static bool GetSize(const std::string& filename, size_t* size);
+
+ protected:
+ virtual void DoClose();
+
+ FILE* file_;
+
+ private:
+ DISALLOW_EVIL_CONSTRUCTORS(FileStream);
+};
+
+// A stream that caps the output at a certain size, dropping content from the
+// middle of the logical stream and maintaining equal parts of the start/end of
+// the logical stream.
+class CircularFileStream : public FileStream {
+ public:
+ explicit CircularFileStream(size_t max_size);
+
+ virtual bool Open(const std::string& filename, const char* mode, int* error);
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error);
+ virtual StreamResult Write(const void* data, size_t data_len,
+ size_t* written, int* error);
+
+ private:
+ enum ReadSegment {
+ READ_MARKED, // Read 0 .. marked_position_
+ READ_MIDDLE, // Read position_ .. file_size
+ READ_LATEST, // Read marked_position_ .. position_ if the buffer was
+ // overwritten or 0 .. position_ otherwise.
+ };
+
+ size_t max_write_size_;
+ size_t position_;
+ size_t marked_position_;
+ size_t last_write_position_;
+ ReadSegment read_segment_;
+ size_t read_segment_available_;
+};
+
+// A stream which pushes writes onto a separate thread and
+// returns from the write call immediately.
+class AsyncWriteStream : public StreamInterface {
+ public:
+ // Takes ownership of the stream, but not the thread.
+ AsyncWriteStream(StreamInterface* stream, rtc::Thread* write_thread)
+ : stream_(stream),
+ write_thread_(write_thread),
+ state_(stream ? stream->GetState() : SS_CLOSED) {
+ }
+
+ virtual ~AsyncWriteStream();
+
+ // StreamInterface Interface
+ virtual StreamState GetState() const { return state_; }
+ // This is needed by some stream writers, such as RtpDumpWriter.
+ virtual bool GetPosition(size_t* position) const;
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error);
+ virtual StreamResult Write(const void* data, size_t data_len,
+ size_t* written, int* error);
+ virtual void Close();
+ virtual bool Flush();
+
+ protected:
+ // From MessageHandler
+ virtual void OnMessage(rtc::Message* pmsg);
+ virtual void ClearBufferAndWrite();
+
+ private:
+ rtc::scoped_ptr<StreamInterface> stream_;
+ Thread* write_thread_;
+ StreamState state_;
+ Buffer buffer_;
+ mutable CriticalSection crit_stream_;
+ CriticalSection crit_buffer_;
+
+ DISALLOW_EVIL_CONSTRUCTORS(AsyncWriteStream);
+};
+
+
+#if defined(WEBRTC_POSIX) && !defined(__native_client__)
+// A FileStream that is actually not a file, but the output or input of a
+// sub-command. See "man 3 popen" for documentation of the underlying OS popen()
+// function.
+class POpenStream : public FileStream {
+ public:
+ POpenStream() : wait_status_(-1) {}
+ virtual ~POpenStream();
+
+ virtual bool Open(const std::string& subcommand, const char* mode,
+ int* error);
+ // Same as Open(). shflag is ignored.
+ virtual bool OpenShare(const std::string& subcommand, const char* mode,
+ int shflag, int* error);
+
+ // Returns the wait status from the last Close() of an Open()'ed stream, or
+ // -1 if no Open()+Close() has been done on this object. Meaning of the number
+ // is documented in "man 2 wait".
+ int GetWaitStatus() const { return wait_status_; }
+
+ protected:
+ virtual void DoClose();
+
+ private:
+ int wait_status_;
+};
+#endif // WEBRTC_POSIX
+
+///////////////////////////////////////////////////////////////////////////////
+// MemoryStream is a simple implementation of a StreamInterface over in-memory
+// data. Data is read and written at the current seek position. Reads return
+// end-of-stream when they reach the end of data. Writes actually extend the
+// end of data mark.
+///////////////////////////////////////////////////////////////////////////////
+
+class MemoryStreamBase : public StreamInterface {
+ public:
+ virtual StreamState GetState() const;
+ virtual StreamResult Read(void* buffer, size_t bytes, size_t* bytes_read,
+ int* error);
+ virtual StreamResult Write(const void* buffer, size_t bytes,
+ size_t* bytes_written, int* error);
+ virtual void Close();
+ virtual bool SetPosition(size_t position);
+ virtual bool GetPosition(size_t* position) const;
+ virtual bool GetSize(size_t* size) const;
+ virtual bool GetAvailable(size_t* size) const;
+ virtual bool ReserveSize(size_t size);
+
+ char* GetBuffer() { return buffer_; }
+ const char* GetBuffer() const { return buffer_; }
+
+ protected:
+ MemoryStreamBase();
+
+ virtual StreamResult DoReserve(size_t size, int* error);
+
+ // Invariant: 0 <= seek_position <= data_length_ <= buffer_length_
+ char* buffer_;
+ size_t buffer_length_;
+ size_t data_length_;
+ size_t seek_position_;
+
+ private:
+ DISALLOW_EVIL_CONSTRUCTORS(MemoryStreamBase);
+};
+
+// MemoryStream dynamically resizes to accomodate written data.
+
+class MemoryStream : public MemoryStreamBase {
+ public:
+ MemoryStream();
+ explicit MemoryStream(const char* data); // Calls SetData(data, strlen(data))
+ MemoryStream(const void* data, size_t length); // Calls SetData(data, length)
+ virtual ~MemoryStream();
+
+ void SetData(const void* data, size_t length);
+
+ protected:
+ virtual StreamResult DoReserve(size_t size, int* error);
+ // Memory Streams are aligned for efficiency.
+ static const int kAlignment = 16;
+ char* buffer_alloc_;
+};
+
+// ExternalMemoryStream adapts an external memory buffer, so writes which would
+// extend past the end of the buffer will return end-of-stream.
+
+class ExternalMemoryStream : public MemoryStreamBase {
+ public:
+ ExternalMemoryStream();
+ ExternalMemoryStream(void* data, size_t length);
+ virtual ~ExternalMemoryStream();
+
+ void SetData(void* data, size_t length);
+};
+
+// FifoBuffer allows for efficient, thread-safe buffering of data between
+// writer and reader. As the data can wrap around the end of the buffer,
+// MemoryStreamBase can't help us here.
+
+class FifoBuffer : public StreamInterface {
+ public:
+ // Creates a FIFO buffer with the specified capacity.
+ explicit FifoBuffer(size_t length);
+ // Creates a FIFO buffer with the specified capacity and owner
+ FifoBuffer(size_t length, Thread* owner);
+ virtual ~FifoBuffer();
+ // Gets the amount of data currently readable from the buffer.
+ bool GetBuffered(size_t* data_len) const;
+ // Resizes the buffer to the specified capacity. Fails if data_length_ > size
+ bool SetCapacity(size_t length);
+
+ // Read into |buffer| with an offset from the current read position, offset
+ // is specified in number of bytes.
+ // This method doesn't adjust read position nor the number of available
+ // bytes, user has to call ConsumeReadData() to do this.
+ StreamResult ReadOffset(void* buffer, size_t bytes, size_t offset,
+ size_t* bytes_read);
+
+ // Write |buffer| with an offset from the current write position, offset is
+ // specified in number of bytes.
+ // This method doesn't adjust the number of buffered bytes, user has to call
+ // ConsumeWriteBuffer() to do this.
+ StreamResult WriteOffset(const void* buffer, size_t bytes, size_t offset,
+ size_t* bytes_written);
+
+ // StreamInterface methods
+ virtual StreamState GetState() const;
+ virtual StreamResult Read(void* buffer, size_t bytes,
+ size_t* bytes_read, int* error);
+ virtual StreamResult Write(const void* buffer, size_t bytes,
+ size_t* bytes_written, int* error);
+ virtual void Close();
+ virtual const void* GetReadData(size_t* data_len);
+ virtual void ConsumeReadData(size_t used);
+ virtual void* GetWriteBuffer(size_t* buf_len);
+ virtual void ConsumeWriteBuffer(size_t used);
+ virtual bool GetWriteRemaining(size_t* size) const;
+
+ private:
+ // Helper method that implements ReadOffset. Caller must acquire a lock
+ // when calling this method.
+ StreamResult ReadOffsetLocked(void* buffer, size_t bytes, size_t offset,
+ size_t* bytes_read);
+
+ // Helper method that implements WriteOffset. Caller must acquire a lock
+ // when calling this method.
+ StreamResult WriteOffsetLocked(const void* buffer, size_t bytes,
+ size_t offset, size_t* bytes_written);
+
+ StreamState state_; // keeps the opened/closed state of the stream
+ scoped_ptr<char[]> buffer_; // the allocated buffer
+ size_t buffer_length_; // size of the allocated buffer
+ size_t data_length_; // amount of readable data in the buffer
+ size_t read_position_; // offset to the readable data
+ Thread* owner_; // stream callbacks are dispatched on this thread
+ mutable CriticalSection crit_; // object lock
+ DISALLOW_EVIL_CONSTRUCTORS(FifoBuffer);
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+class LoggingAdapter : public StreamAdapterInterface {
+ public:
+ LoggingAdapter(StreamInterface* stream, LoggingSeverity level,
+ const std::string& label, bool hex_mode = false);
+
+ void set_label(const std::string& label);
+
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error);
+ virtual StreamResult Write(const void* data, size_t data_len,
+ size_t* written, int* error);
+ virtual void Close();
+
+ protected:
+ virtual void OnEvent(StreamInterface* stream, int events, int err);
+
+ private:
+ LoggingSeverity level_;
+ std::string label_;
+ bool hex_mode_;
+ LogMultilineState lms_;
+
+ DISALLOW_EVIL_CONSTRUCTORS(LoggingAdapter);
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// StringStream - Reads/Writes to an external std::string
+///////////////////////////////////////////////////////////////////////////////
+
+class StringStream : public StreamInterface {
+ public:
+ explicit StringStream(std::string& str);
+ explicit StringStream(const std::string& str);
+
+ virtual StreamState GetState() const;
+ virtual StreamResult Read(void* buffer, size_t buffer_len,
+ size_t* read, int* error);
+ virtual StreamResult Write(const void* data, size_t data_len,
+ size_t* written, int* error);
+ virtual void Close();
+ virtual bool SetPosition(size_t position);
+ virtual bool GetPosition(size_t* position) const;
+ virtual bool GetSize(size_t* size) const;
+ virtual bool GetAvailable(size_t* size) const;
+ virtual bool ReserveSize(size_t size);
+
+ private:
+ std::string& str_;
+ size_t read_pos_;
+ bool read_only_;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// StreamReference - A reference counting stream adapter
+///////////////////////////////////////////////////////////////////////////////
+
+// Keep in mind that the streams and adapters defined in this file are
+// not thread-safe, so this has limited uses.
+
+// A StreamRefCount holds the reference count and a pointer to the
+// wrapped stream. It deletes the wrapped stream when there are no
+// more references. We can then have multiple StreamReference
+// instances pointing to one StreamRefCount, all wrapping the same
+// stream.
+
+class StreamReference : public StreamAdapterInterface {
+ class StreamRefCount;
+ public:
+ // Constructor for the first reference to a stream
+ // Note: get more references through NewReference(). Use this
+ // constructor only once on a given stream.
+ explicit StreamReference(StreamInterface* stream);
+ StreamInterface* GetStream() { return stream(); }
+ StreamInterface* NewReference();
+ virtual ~StreamReference();
+
+ private:
+ class StreamRefCount {
+ public:
+ explicit StreamRefCount(StreamInterface* stream)
+ : stream_(stream), ref_count_(1) {
+ }
+ void AddReference() {
+ CritScope lock(&cs_);
+ ++ref_count_;
+ }
+ void Release() {
+ int ref_count;
+ { // Atomic ops would have been a better fit here.
+ CritScope lock(&cs_);
+ ref_count = --ref_count_;
+ }
+ if (ref_count == 0) {
+ delete stream_;
+ delete this;
+ }
+ }
+ private:
+ StreamInterface* stream_;
+ int ref_count_;
+ CriticalSection cs_;
+ DISALLOW_EVIL_CONSTRUCTORS(StreamRefCount);
+ };
+
+ // Constructor for adding references
+ explicit StreamReference(StreamRefCount* stream_ref_count,
+ StreamInterface* stream);
+
+ StreamRefCount* stream_ref_count_;
+ DISALLOW_EVIL_CONSTRUCTORS(StreamReference);
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+// Flow attempts to move bytes from source to sink via buffer of size
+// buffer_len. The function returns SR_SUCCESS when source reaches
+// end-of-stream (returns SR_EOS), and all the data has been written successful
+// to sink. Alternately, if source returns SR_BLOCK or SR_ERROR, or if sink
+// returns SR_BLOCK, SR_ERROR, or SR_EOS, then the function immediately returns
+// with the unexpected StreamResult value.
+// data_len is the length of the valid data in buffer. in case of error
+// this is the data that read from source but can't move to destination.
+// as a pass in parameter, it indicates data in buffer that should move to sink
+StreamResult Flow(StreamInterface* source,
+ char* buffer, size_t buffer_len,
+ StreamInterface* sink, size_t* data_len = NULL);
+
+///////////////////////////////////////////////////////////////////////////////
+
+} // namespace rtc
+
+#endif // WEBRTC_BASE_STREAM_H_