GUAC-236: Assemble entire image data prior to decoding. Switch to simple decoder function (no struct).

This commit is contained in:
Michael Jumper 2016-02-27 23:31:07 -08:00
parent 3661cadf4e
commit a15a86ed00
8 changed files with 116 additions and 221 deletions

View File

@ -30,14 +30,16 @@
#include "webp.h" #include "webp.h"
#endif #endif
#include <cairo/cairo.h>
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
guacenc_decoder_mapping guacenc_decoder_map[] = { guacenc_decoder_mapping guacenc_decoder_map[] = {
{"image/png", &guacenc_png_decoder}, {"image/png", guacenc_png_decoder},
{"image/jpeg", &guacenc_jpeg_decoder}, {"image/jpeg", guacenc_jpeg_decoder},
#ifdef ENABLE_WEBP #ifdef ENABLE_WEBP
{"image/webp", &guacenc_webp_decoder}, {"image/webp", guacenc_webp_decoder},
#endif #endif
{NULL, NULL} {NULL, NULL}
}; };
@ -78,9 +80,12 @@ guacenc_image_stream* guacenc_image_stream_alloc(int mask, int index,
stream->y = y; stream->y = y;
/* Associate with corresponding decoder */ /* Associate with corresponding decoder */
guacenc_decoder* decoder = stream->decoder = guacenc_get_decoder(mimetype); stream->decoder = guacenc_get_decoder(mimetype);
if (decoder != NULL)
decoder->init_handler(stream); /* Allocate initial buffer */
stream->length = 0;
stream->max_length = GUACENC_IMAGE_STREAM_INITIAL_LENGTH;
stream->buffer = (unsigned char*) malloc(stream->max_length);
return stream; return stream;
@ -89,12 +94,27 @@ guacenc_image_stream* guacenc_image_stream_alloc(int mask, int index,
int guacenc_image_stream_receive(guacenc_image_stream* stream, int guacenc_image_stream_receive(guacenc_image_stream* stream,
unsigned char* data, int length) { unsigned char* data, int length) {
/* Invoke data handler of corresponding decoder (if any) */ /* Allocate more space if necessary */
guacenc_decoder* decoder = stream->decoder; if (stream->max_length - stream->length < length) {
if (decoder != NULL)
return decoder->data_handler(stream, data, length);
/* If there is no decoder, simply return success */ /* Calculate a reasonable new max length guaranteed to fit buffer */
int new_max_length = stream->max_length * 2 + length;
/* Attempt to resize buffer */
unsigned char* new_buffer =
(unsigned char*) realloc(stream->buffer, new_max_length);
if (new_buffer == NULL)
return 1;
/* Store updated buffer and size */
stream->buffer = new_buffer;
stream->max_length = new_max_length;
}
/* Append data */
memcpy(stream->buffer + stream->length, data, length);
stream->length += length;
return 0; return 0;
} }
@ -102,12 +122,20 @@ int guacenc_image_stream_receive(guacenc_image_stream* stream,
int guacenc_image_stream_end(guacenc_image_stream* stream, int guacenc_image_stream_end(guacenc_image_stream* stream,
guacenc_buffer* buffer) { guacenc_buffer* buffer) {
/* Invoke end handler of corresponding decoder (if any) */
guacenc_decoder* decoder = stream->decoder;
if (decoder != NULL)
return decoder->end_handler(stream, buffer);
/* If there is no decoder, simply return success */ /* If there is no decoder, simply return success */
guacenc_decoder* decoder = stream->decoder;
if (decoder == NULL)
return 0;
/* Decode received data to a Cairo surface */
cairo_surface_t* surface = stream->decoder(stream->buffer, stream->length);
if (surface == NULL)
return 1;
/* Draw surface to buffer */
cairo_set_source_surface(buffer->cairo, surface, stream->x, stream->y);
cairo_fill(buffer->cairo);
cairo_surface_destroy(surface);
return 0; return 0;
} }
@ -118,10 +146,8 @@ int guacenc_image_stream_free(guacenc_image_stream* stream) {
if (stream == NULL) if (stream == NULL)
return 0; return 0;
/* Invoke free handler for decoder (if associated) */ /* Free image buffer */
guacenc_decoder* decoder = stream->decoder; free(stream->buffer);
if (decoder != NULL)
decoder->free_handler(stream);
/* Free actual stream */ /* Free actual stream */
free(stream); free(stream);

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@ -26,11 +26,31 @@
#include "config.h" #include "config.h"
#include "buffer.h" #include "buffer.h"
#include <cairo/cairo.h>
/** /**
* A decoder implementation which processes arbitrary image data of a * The initial number of bytes to allocate for the image data buffer. If this
* particular type. Image data is fed explicitly into the decoder as chunks. * buffer is not sufficiently larged, it will be dynamically reallocated as it
* grows.
*/ */
typedef struct guacenc_decoder guacenc_decoder; #define GUACENC_IMAGE_STREAM_INITIAL_LENGTH 4096
/**
* Callback function which is provided raw, encoded image data of the given
* length. The function is expected to return a new Cairo surface which will
* later (by guacenc) be freed via cairo_surface_destroy().
*
* @param data
* The raw encoded image data that this function must decode.
*
* @param length
* The length of the image data, in bytes.
*
* @return
* A newly-allocated Cairo surface containing the decoded image, or NULL
* or decoding fails.
*/
typedef cairo_surface_t* guacenc_decoder(unsigned char* data, int length);
/** /**
* The current state of an allocated Guacamole image stream. * The current state of an allocated Guacamole image stream.
@ -60,117 +80,34 @@ typedef struct guacenc_image_stream {
*/ */
int y; int y;
/**
* Buffer of image data which will be built up over time as chunks are
* received via "blob" instructions. This will ultimately be passed in its
* entirety to the decoder function.
*/
unsigned char* buffer;
/**
* The number of bytes currently stored in the buffer.
*/
int length;
/**
* The maximum number of bytes that can be stored in the current buffer
* before it must be reallocated.
*/
int max_length;
/** /**
* The decoder to use when decoding the raw data received along this * The decoder to use when decoding the raw data received along this
* stream, or NULL if no such decoder exists. * stream, or NULL if no such decoder exists.
*/ */
guacenc_decoder* decoder; guacenc_decoder* decoder;
/**
* Arbitrary implementation-specific data associated with the stream.
*/
void* data;
} guacenc_image_stream; } guacenc_image_stream;
/** /**
* Callback function which is invoked when a decoder has been assigned to an * Mapping of image mimetype to corresponding decoder function.
* image stream.
*
* @param stream
* The image stream that the decoder has been assigned to.
*
* @return
* Zero if initialization was successful, non-zero otherwise.
*/
typedef int guacenc_decoder_init_handler(guacenc_image_stream* stream);
/**
* Callback function which is invoked when data has been received along an
* image stream with an associated decoder.
*
* @param stream
* The image stream that the decoder was assigned to.
*
* @param data
* The chunk of data received along the image stream.
*
* @param length
* The length of the chunk of data received, in bytes.
*
* @return
* Zero if the provided data was processed successfully, non-zero
* otherwise.
*/
typedef int guacenc_decoder_data_handler(guacenc_image_stream* stream,
unsigned char* data, int length);
/**
* Callback function which is invoked when an image stream with an associated
* decoder has ended (reached end-of-stream). The image stream will contain
* the required meta-information describing the drawing operation, including
* the destination X/Y coordinates.
*
* @param stream
* The image stream that has ended.
*
* @param buffer
* The buffer to which the decoded image should be drawn.
*
* @return
* Zero if the end of the stream has been processed successfully and the
* resulting image has been rendered to the given buffer, non-zero
* otherwise.
*/
typedef int guacenc_decoder_end_handler(guacenc_image_stream* stream,
guacenc_buffer* buffer);
/**
* Callback function which will be invoked when the data associated with an
* image stream must be freed. This may happen at any time, and will not
* necessarily occur only after the image stream has ended. It is possible
* that an image stream will be in-progress at the end of a protocol dump, thus
* the memory associated with the stream will need to be freed without ever
* ending.
*
* @param stream
* The stream whose associated data must be freed.
*
* @return
* Zero if the data was successfully freed, non-zero otherwise.
*/
typedef int guacenc_decoder_free_handler(guacenc_image_stream* stream);
struct guacenc_decoder {
/**
* Callback invoked when this decoder has just been assigned to an image
* stream.
*/
guacenc_decoder_init_handler* init_handler;
/**
* Callback invoked when data has been received along an image stream to
* which this decoder has been assigned.
*/
guacenc_decoder_data_handler* data_handler;
/**
* Callback invoked when an image stream to which this decoder has been
* assigned has ended (reached end-of-stream).
*/
guacenc_decoder_end_handler* end_handler;
/**
* Callback invoked when data associated with an image stream by this
* decoder must be freed.
*/
guacenc_decoder_free_handler* free_handler;
};
/**
* Mapping of image mimetype to corresponding decoder.
*/ */
typedef struct guacenc_decoder_mapping { typedef struct guacenc_decoder_mapping {
@ -180,8 +117,8 @@ typedef struct guacenc_decoder_mapping {
const char* mimetype; const char* mimetype;
/** /**
* The decoder to use when an image stream of the associated mimetype is * The decoder function to use when an image stream of the associated
* received. * mimetype is received.
*/ */
guacenc_decoder* decoder; guacenc_decoder* decoder;
@ -238,9 +175,9 @@ guacenc_image_stream* guacenc_image_stream_alloc(int mask, int index,
const char* mimetype, int x, int y); const char* mimetype, int x, int y);
/** /**
* Signals the decoder of the given image stream that a chunk of image data * Appends newly-received data to the internal buffer of the given image
* has been received. If no decoder is associated with the given image stream, * stream, such that the entire received image can be fed to the decoder as one
* this function has no effect. * buffer once the stream ends.
* *
* @param stream * @param stream
* The image stream that received the data. * The image stream that received the data.
@ -252,18 +189,19 @@ guacenc_image_stream* guacenc_image_stream_alloc(int mask, int index,
* The length of the chunk of data received, in bytes. * The length of the chunk of data received, in bytes.
* *
* @return * @return
* Zero if the given data was handled successfully by the decoder, or * Zero if the given data was successfully appended to the in-progress
* non-zero if an error occurs. * image, non-zero if an error occurs.
*/ */
int guacenc_image_stream_receive(guacenc_image_stream* stream, int guacenc_image_stream_receive(guacenc_image_stream* stream,
unsigned char* data, int length); unsigned char* data, int length);
/** /**
* Signals the decoder of the given image stream that no more data will be * Marks the end of the given image stream (no more data will be received) and
* received and the image should be written to the given buffer as-is. If no * invokes the associated decoder. The decoded image will be written to the
* decoder is associated with the given image stream, this function has no * given buffer as-is. If no decoder is associated with the given image stream,
* effect. Meta-information describing the image draw operation itself is * this function has no effect. Meta-information describing the image draw
* stored within the guacenc_image_stream. * operation itself is pulled from the guacenc_image_stream, having been stored
* there when the image stream was created.
* *
* @param stream * @param stream
* The image stream that has ended. * The image stream that has ended.

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@ -21,37 +21,14 @@
*/ */
#include "config.h" #include "config.h"
#include "buffer.h"
#include "image-stream.h"
#include "jpeg.h" #include "jpeg.h"
#include <cairo/cairo.h>
#include <stdlib.h> #include <stdlib.h>
int guacenc_jpeg_init(guacenc_image_stream* stream) { cairo_surface_t* guacenc_jpeg_decoder(unsigned char* data, int length) {
/* STUB */ /* STUB */
return 0; return NULL;
} }
int guacenc_jpeg_data(guacenc_image_stream* stream, unsigned char* data,
int length) {
/* STUB */
return 0;
}
int guacenc_jpeg_end(guacenc_image_stream* stream, guacenc_buffer* buffer) {
/* STUB */
return 0;
}
int guacenc_jpeg_free(guacenc_image_stream* stream) {
/* STUB */
return 0;
}
guacenc_decoder guacenc_jpeg_decoder = {
.init_handler = guacenc_jpeg_init,
.data_handler = guacenc_jpeg_data,
.end_handler = guacenc_jpeg_end,
.free_handler = guacenc_jpeg_free
};

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@ -29,7 +29,7 @@
/** /**
* Decoder implementation which handles "image/jpeg" images. * Decoder implementation which handles "image/jpeg" images.
*/ */
extern guacenc_decoder guacenc_jpeg_decoder; guacenc_decoder guacenc_jpeg_decoder;
#endif #endif

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@ -21,37 +21,14 @@
*/ */
#include "config.h" #include "config.h"
#include "buffer.h"
#include "image-stream.h"
#include "png.h" #include "png.h"
#include <cairo/cairo.h>
#include <stdlib.h> #include <stdlib.h>
int guacenc_png_init(guacenc_image_stream* stream) { cairo_surface_t* guacenc_png_decoder(unsigned char* data, int length) {
/* STUB */ /* STUB */
return 0; return NULL;
} }
int guacenc_png_data(guacenc_image_stream* stream, unsigned char* data,
int length) {
/* STUB */
return 0;
}
int guacenc_png_end(guacenc_image_stream* stream, guacenc_buffer* buffer) {
/* STUB */
return 0;
}
int guacenc_png_free(guacenc_image_stream* stream) {
/* STUB */
return 0;
}
guacenc_decoder guacenc_png_decoder = {
.init_handler = guacenc_png_init,
.data_handler = guacenc_png_data,
.end_handler = guacenc_png_end,
.free_handler = guacenc_png_free
};

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@ -29,7 +29,7 @@
/** /**
* Decoder implementation which handles "image/png" images. * Decoder implementation which handles "image/png" images.
*/ */
extern guacenc_decoder guacenc_png_decoder; guacenc_decoder guacenc_png_decoder;
#endif #endif

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@ -21,37 +21,14 @@
*/ */
#include "config.h" #include "config.h"
#include "buffer.h"
#include "image-stream.h"
#include "webp.h" #include "webp.h"
#include <cairo/cairo.h>
#include <stdlib.h> #include <stdlib.h>
int guacenc_webp_init(guacenc_image_stream* stream) { cairo_surface_t* guacenc_webp_decoder(unsigned char* data, int length) {
/* STUB */ /* STUB */
return 0; return NULL;
} }
int guacenc_webp_data(guacenc_image_stream* stream, unsigned char* data,
int length) {
/* STUB */
return 0;
}
int guacenc_webp_end(guacenc_image_stream* stream, guacenc_buffer* buffer) {
/* STUB */
return 0;
}
int guacenc_webp_free(guacenc_image_stream* stream) {
/* STUB */
return 0;
}
guacenc_decoder guacenc_webp_decoder = {
.init_handler = guacenc_webp_init,
.data_handler = guacenc_webp_data,
.end_handler = guacenc_webp_end,
.free_handler = guacenc_webp_free
};

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@ -29,7 +29,7 @@
/** /**
* Decoder implementation which handles "image/webp" images. * Decoder implementation which handles "image/webp" images.
*/ */
extern guacenc_decoder guacenc_webp_decoder; guacenc_decoder guacenc_webp_decoder;
#endif #endif