ru_tts

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/* sink.c -- Interactions with general data consuming callback
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 *
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 * Copyright (C) 1990, 1991 Speech Research Laboratory, Minsk
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 * Copyright (C) 2005 Igor Poretsky <poretsky@mlbox.ru>
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 * Copyright (C) 2021 Boris Lobanov <lobbormef@gmail.com>
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 * Copyright (C) 2021 Alexander Ivanov <ivalex01@gmail.com>
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 *
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 * SPDX-License-Identifier: MIT
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 */
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include "ru_tts.h"
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#include "sink.h"
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/* Initialize sink control structure */
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void sink_setup(sink_t *consumer, void *buffer, size_t bufsize, ru_tts_callback function, void *user_data)
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{
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  consumer->buffer = buffer;
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  consumer->buffer_offset = 0;
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  consumer->bufsize = bufsize;
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  consumer->status = 0;
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  consumer->user_data = user_data;
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  consumer->function = function;
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  consumer->custom_reset = NULL;
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}
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/*
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 * Reset action.
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 *
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 * Performs custom reset function if specified.
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 * Otherwise simply resets buffer offset.
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 */
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void sink_reset(sink_t *consumer)
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{
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  if (consumer->custom_reset)
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    consumer->custom_reset(consumer);
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  else consumer->buffer_offset = 0;
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}
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/* Pass data to the sink function */
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void sink_flush(sink_t *consumer)
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{
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  if (consumer->function && consumer->buffer && consumer->buffer_offset)
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    consumer->status |= consumer->function(consumer->buffer, consumer->buffer_offset, consumer->user_data);
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  sink_reset(consumer);
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}
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/* Pass one byte of data */
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void sink_put(sink_t *consumer, int8_t byte)
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{
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  ((int8_t *)(consumer->buffer))[consumer->buffer_offset++] = byte;
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  if (consumer->buffer_offset >= consumer->bufsize)
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    sink_flush(consumer);
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}
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/*
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 * Pass a block of data.
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 *
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 * Potentially may cause buffer overflow since this condition
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 * is not checked during data transfer, but only afterwards.
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 */
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void sink_write(sink_t *consumer, const uint8_t *block, size_t size)
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{
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  memcpy((uint8_t *)consumer->buffer + consumer->buffer_offset, block, size);
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  consumer->buffer_offset += size;
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  if (consumer->buffer_offset >= consumer->bufsize)
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    sink_flush(consumer);
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}
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/* Forget last byte if possible */
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void sink_back(sink_t *consumer)
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{
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  if (consumer->buffer_offset)
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    consumer->buffer_offset--;
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}
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/*
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 * Replace the last byte in the consumer buffer.
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 * If the buffer is empty, acts just like sink_put().
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 */
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void sink_replace(sink_t *consumer, uint8_t byte)
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{
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  sink_back(consumer);
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  sink_put(consumer, byte);
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}
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/*
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 * Get last byte value from the consumer buffer.
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 * Returns -1 if the buffer is empty.
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 */
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int sink_last(sink_t *consumer)
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{
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  return (consumer->buffer_offset) ? ((uint8_t *)(consumer->buffer))[consumer->buffer_offset - 1] : -1;
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}
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