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#ifndef AWS_HTTP_WEBSOCKET_DECODER_H
#define AWS_HTTP_WEBSOCKET_DECODER_H
/**
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
* SPDX-License-Identifier: Apache-2.0.
*/
#include <aws/http/private/websocket_impl.h>
/* Called when the non-payload portion of a frame has been decoded. */
typedef int(aws_websocket_decoder_frame_fn)(const struct aws_websocket_frame *frame, void *user_data);
/* Called repeatedly as the payload is decoded. If a mask was used, the data has been unmasked. */
typedef int(aws_websocket_decoder_payload_fn)(struct aws_byte_cursor data, void *user_data);
/**
* Each state consumes data and/or moves decoder to a subsequent state.
*/
enum aws_websocket_decoder_state {
AWS_WEBSOCKET_DECODER_STATE_INIT,
AWS_WEBSOCKET_DECODER_STATE_OPCODE_BYTE,
AWS_WEBSOCKET_DECODER_STATE_LENGTH_BYTE,
AWS_WEBSOCKET_DECODER_STATE_EXTENDED_LENGTH,
AWS_WEBSOCKET_DECODER_STATE_MASKING_KEY_CHECK,
AWS_WEBSOCKET_DECODER_STATE_MASKING_KEY,
AWS_WEBSOCKET_DECODER_STATE_PAYLOAD_CHECK,
AWS_WEBSOCKET_DECODER_STATE_PAYLOAD,
AWS_WEBSOCKET_DECODER_STATE_FRAME_END,
AWS_WEBSOCKET_DECODER_STATE_DONE,
};
struct aws_websocket_decoder {
enum aws_websocket_decoder_state state;
uint64_t state_bytes_processed; /* For multi-byte states, the number of bytes processed so far */
uint8_t state_cache[8]; /* For multi-byte states to cache data that might be split across packets */
struct aws_websocket_frame current_frame; /* Data about current frame being decoded */
bool expecting_continuation_data_frame; /* True when the next data frame must be CONTINUATION frame */
/* True while processing a TEXT "message" (from the start of a TEXT frame,
* until the end of the TEXT or CONTINUATION frame with the FIN bit set). */
bool processing_text_message;
struct aws_utf8_decoder *text_message_validator;
void *user_data;
aws_websocket_decoder_frame_fn *on_frame;
aws_websocket_decoder_payload_fn *on_payload;
};
AWS_EXTERN_C_BEGIN
AWS_HTTP_API
void aws_websocket_decoder_init(
struct aws_websocket_decoder *decoder,
struct aws_allocator *alloc,
aws_websocket_decoder_frame_fn *on_frame,
aws_websocket_decoder_payload_fn *on_payload,
void *user_data);
AWS_HTTP_API
void aws_websocket_decoder_clean_up(struct aws_websocket_decoder *decoder);
/**
* Returns when all data is processed, or a frame and its payload have completed.
* `data` will be advanced to reflect the amount of data processed by this call.
* `frame_complete` will be set true if this call returned due to completion of a frame.
* The `on_frame` and `on_payload` callbacks may each be invoked once as a result of this call.
* If an error occurs, the decoder is invalid forevermore.
*/
AWS_HTTP_API int aws_websocket_decoder_process(
struct aws_websocket_decoder *decoder,
struct aws_byte_cursor *data,
bool *frame_complete);
AWS_EXTERN_C_END
#endif /* AWS_HTTP_WEBSOCKET_DECODER_H */
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