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/*
* Copyright (c) 2017-2019 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* Wrapper around event scheduler
*/
#ifndef streamBuffer_h
#define streamBuffer_h
#include <parc/algol/parc_EventQueue.h>
#include <stdbool.h>
void streamBuffer_Destroy(PARCEventQueue **bufferPtr);
/**
* @function streamBuffer_SetWatermark
* @abstract Sets the read and/or write watermarks
* @discussion
* For a read watermark, when there is at least <code>low</code> bytes
* available to read, the read callback will be fired. If the bytes in the
* buffer exceed <code>high</code>, the stream buffer will stop reading from the
* network.
*
* For a write watermark, when the bytes in the buffer fall below
* <code>low</code>, the write callback is fired. The <code>high</code>
* watermark limits stream filters and shapers from exceeding that threashold on
* what they write to the buffer.
*
*/
void streamBuffer_SetWatermark(PARCEventQueue *buffer, bool setRead,
bool setWrite, size_t low, size_t high);
/**
* @function streamBuffer_Flush
* @abstract The buffer will read/write more data if available
*
* @return -1 error, 0 no more data, 1 more data
*/
int streamBuffer_Flush(PARCEventQueue *buffer, bool flushRead, bool flushWrite);
/**
* @function streamBuffer_FlushCheckpoint
* @abstract Flushes the stream, checkpointing all data in the buffer
*/
int streamBuffer_FlushCheckpoint(PARCEventQueue *buffer, bool flushRead,
bool flushWrite);
/**
* @function streamBuffer_FlushFinished
* @abstract Flush the stream and indicate the end of new data
*/
int streamBuffer_FlushFinished(PARCEventQueue *buffer, bool flushRead,
bool flushWrite);
/**
* @typedef StreamBufferReadWriteCallback
* @abstract Callback when data is available or write space available
* @constant user_data opaque data passed to
* <code>StreamBuffer_SetCallbacks()</code>
*/
typedef void(StreamBufferReadWriteCallback)(PARCEventQueue *buffer,
void *user_data);
/**
* @typedef StreamBufferEventCallback
* @abstract Callback on error or other event on the stream buffer
* @constant what logical or of STREAM events. STREAM_READING and
* STREAM_WRITING indicate if the error was on the read or write direction. The
* conditions may be STREAM_ERROR, STREAM_EOF, STREAM_TIMEOUT, or
* STREAM_CONNECTED.
* @constant user_data opaque data passed to
* <code>StreamBuffer_SetCallbacks()</code>
*/
typedef void(StreamBufferEventCallback)(PARCEventQueue *buffer, short what,
void *user_data);
/**
* Changes the callbacks for a buffer event.
*
* @param bufev the buffer event object for which to change callbacks
* @param readcb callback to invoke when there is data to be read, or NULL if
* no callback is desired
* @param writecb callback to invoke when the file descriptor is ready for
* writing, or NULL if no callback is desired
* @param eventcb callback to invoke when there is an event on the file
* descriptor
* @param cbarg an argument that will be supplied to each of the callbacks
* (readcb, writecb, and errorcb)
* @see parcEventQueue_Create()
*/
void streamBuffer_SetCallbacks(PARCEventQueue *buffer,
PARCEventQueue_Callback *readCallback,
PARCEventQueue_Callback *writeCallback,
PARCEventQueue_EventCallback *eventCallback,
void *user_data);
/**
* @function StreamBuffer_EnableCallbacks
* @abstract Enables specified callbacks. Does not affect others.
* @discussion
* Enables disabled callbacks. If a callback is already enabled, has no
* effect. A "false" value does not disable it.
*/
void streamBuffer_EnableCallbacks(PARCEventQueue *buffer, bool enableRead,
bool enableWrite);
/**
* @function StreamBuffer_DisableCallbacks
* @abstract Disables specified callbacks. Does not affect others.
* @discussion
* Disables enabled callbacks. If a callback is already disabled, has no
* effect. A "false" value does not enable it.
*/
void streamBuffer_DisableCallbacks(PARCEventQueue *buffer, bool disableRead,
bool disableWrite);
#endif // streamBuffer_h
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