1 files changed, 265 insertions, 0 deletions
diff --git a/filter.c b/filter.c
new file mode 100644
index 0000000..5b6c158
--- /dev/null
+++ b/filter.c
@@ -0,0 +1,265 @@
+#include "php.h"
+#include "lzf.h"
+
+#define LZF_BLOCKSIZE	(1024 * 64 - 1)
+
+typedef struct {
+	char signature[3];
+	char usize[2];
+} lzf_header_uncompressed;
+
+typedef struct {
+	char signature[3];
+	char csize[2];
+	char usize[2];
+} lzf_header_compressed;
+
+typedef struct _php_lzf_compress_filter {
+	int persistent;
+	char *buffer;
+	size_t buffer_pos;
+} php_lzf_filter_state;
+
+static void fill_header_compressed(lzf_header_compressed *header, size_t compressed, size_t uncompressed)
+{
+	/* Copied from liblzf/lzf.c */
+	
+	header->signature[0] = 'Z';
+	header->signature[1] = 'V';
+	header->signature[2] = 1;
+	header->csize[0] = compressed >> 8;
+	header->csize[1] = compressed & 0xff;
+	header->usize[0] = uncompressed >> 8;
+	header->usize[1] = uncompressed & 0xff;
+}
+
+static void fill_header_uncompressed(lzf_header_uncompressed *header, size_t uncompressed)
+{
+	/* Copied from liblzf/lzf.c */
+	
+	header->signature[0] = 'Z';
+	header->signature[1] = 'V';
+	header->signature[2] = 0;
+	header->usize[0] = uncompressed >> 8;
+	header->usize[1] = uncompressed & 0xff;
+}
+
+static int php_lzf_filter_state_ctor(php_lzf_filter_state *inst, int persistent)
+{
+	inst->persistent = persistent;
+	inst->buffer = pemalloc(LZF_BLOCKSIZE, persistent);
+	inst->buffer_pos = 0;
+
+	return SUCCESS;
+}
+
+static void php_lzf_filter_state_dtor(php_lzf_filter_state *inst TSRMLS_DC)
+{
+	pefree(inst->buffer, inst->persistent);
+}
+
+static int lzf_compress_filter_append_bucket(
+	php_stream *stream,
+	php_stream_filter_status_t *exit_status,
+	php_lzf_filter_state *inst,
+	php_stream_bucket_brigade *buckets_out,
+	int persistent TSRMLS_DC)
+{
+	int status;
+	size_t buffer_size;
+	php_stream_bucket *new_bucket;
+	char *output_buffer;
+
+	/* Allocate buffer with a size of data and (larger) header */
+	output_buffer = pemalloc(inst->buffer_pos + sizeof(lzf_header_compressed), persistent);
+
+	if (!output_buffer)
+		goto fail;
+		
+	/* Try to compress data. */
+	status = lzf_compress(inst->buffer, inst->buffer_pos, output_buffer + sizeof(lzf_header_compressed), inst->buffer_pos);
+
+	/* 
+	 * If we were able to compress data, write compressed block. Otherwise 
+	 * use uncompressed block.
+	 */
+	if (status > 0) {
+		output_buffer = perealloc(output_buffer, status + sizeof(lzf_header_compressed), persistent);
+		fill_header_compressed((lzf_header_compressed *) output_buffer, status, inst->buffer_pos);
+		buffer_size = status + sizeof(lzf_header_compressed);
+	} else {
+		/* Pessimistic case - we still need to memcpy() data */
+		output_buffer = perealloc(output_buffer, inst->buffer_pos + sizeof(lzf_header_uncompressed), persistent);
+		fill_header_uncompressed((lzf_header_uncompressed *) output_buffer, inst->buffer_pos);
+		memcpy(output_buffer + sizeof(lzf_header_uncompressed), inst->buffer, inst->buffer_pos);
+		buffer_size = inst->buffer_pos + sizeof(lzf_header_uncompressed);
+	}
+
+	/* Create new bucket and append it */
+	new_bucket = php_stream_bucket_new(stream, output_buffer, buffer_size, 1, 0 TSRMLS_CC);
+	if (!new_bucket)
+		goto fail_free_buffer;
+
+	php_stream_bucket_append(buckets_out, new_bucket TSRMLS_CC);
+
+	/* Clear our buffer */
+	inst->buffer_pos = 0; 
+	
+	/* Change exit status */
+	*exit_status = PSFS_PASS_ON;
+	
+	return SUCCESS;
+
+fail_free_buffer:
+	pefree(output_buffer, persistent);
+fail:
+	return FAILURE;
+}
+
+static int lzf_compress_append_data(
+	php_stream *stream,
+	php_stream_filter_status_t *exit_status,
+	php_stream_bucket_brigade *buckets_out,
+	php_lzf_filter_state *inst,
+	const char *input_buffer,
+	size_t input_buffer_len,
+	size_t *consumed,
+	int persistent TSRMLS_DC)
+{
+	size_t free_buffer;
+	size_t bytes_to_copy;
+	
+	/* As long as there are data in the input buffer... */
+	while (input_buffer_len) {
+		free_buffer = LZF_BLOCKSIZE - inst->buffer_pos;		/* Free space in buffer */
+		bytes_to_copy = MIN(free_buffer, input_buffer_len);	/* Bytes to copy into buffer */
+
+		/* ... copy as many bytes into buffer as possible */
+		memcpy(inst->buffer + inst->buffer_pos, input_buffer, bytes_to_copy);
+		inst->buffer_pos += bytes_to_copy;
+		input_buffer += bytes_to_copy;
+		input_buffer_len -= bytes_to_copy;
+		(*consumed) += bytes_to_copy;
+
+		/* If the buffer is full, we need to flush it */
+		if (inst->buffer_pos == LZF_BLOCKSIZE) {
+			if (lzf_compress_filter_append_bucket(stream, exit_status, inst, buckets_out, persistent TSRMLS_CC) != SUCCESS)
+				return FAILURE;
+		}
+	}
+	
+	return SUCCESS;
+}
+
+static php_stream_filter_status_t lzf_compress_filter(
+	php_stream *stream,
+	php_stream_filter *thisfilter,
+	php_stream_bucket_brigade *buckets_in,
+	php_stream_bucket_brigade *buckets_out,
+	size_t *bytes_consumed,
+	int flags TSRMLS_DC)
+{
+	size_t consumed = 0;
+	php_lzf_filter_state *inst = (php_lzf_filter_state *) thisfilter->abstract;
+	php_stream_filter_status_t exit_status = PSFS_FEED_ME;
+	php_stream_bucket *bucket = NULL;
+
+	while (buckets_in->head) {
+		bucket = buckets_in->head;
+
+		php_stream_bucket_unlink(bucket TSRMLS_CC);
+
+		if (lzf_compress_append_data(stream, &exit_status, buckets_out, inst, bucket->buf, bucket->buflen, &consumed, 
+				php_stream_is_persistent(stream) TSRMLS_CC) != SUCCESS)
+			goto fail_free_bucket;
+
+		php_stream_bucket_delref(bucket TSRMLS_CC);
+	}
+
+	if (bytes_consumed)
+		*bytes_consumed = consumed;
+
+	if (flags & PSFS_FLAG_FLUSH_CLOSE) {
+		if (lzf_compress_filter_append_bucket(stream, &exit_status, inst, buckets_out, php_stream_is_persistent(stream) TSRMLS_CC) != SUCCESS)
+			goto fail;
+	}
+
+	return exit_status;
+
+fail_free_bucket:
+	if (bucket != NULL)
+		php_stream_bucket_delref(bucket TSRMLS_CC);
+fail:
+	return PSFS_ERR_FATAL;
+}
+
+static php_stream_filter_status_t lzf_decompress_filter(
+	php_stream *stream,
+	php_stream_filter *thisfilter,
+	php_stream_bucket_brigade *buckets_in,
+	php_stream_bucket_brigade *buckets_out,
+	size_t *bytes_consumed,
+	int flags TSRMLS_DC)
+{
+	return PSFS_PASS_ON;
+}
+
+static void lzf_filter_state_dtor(php_stream_filter *thisfilter TSRMLS_DC)
+{
+	assert(thisfilter->abstract != NULL);
+
+	php_lzf_filter_state_dtor((php_lzf_filter_state *) thisfilter->abstract TSRMLS_CC);
+	pefree(thisfilter->abstract, ((php_lzf_filter_state *) thisfilter->abstract)->persistent);
+}
+
+static php_stream_filter_ops lzf_compress_ops = {
+	lzf_compress_filter,
+	lzf_filter_state_dtor,
+	"lzf.compress"
+};
+
+static php_stream_filter_ops lzf_decompress_ops = {
+	lzf_decompress_filter,
+	lzf_filter_state_dtor,
+	"lzf.decompress"
+};
+
+static php_stream_filter *lzf_compress_filter_create(const char *filtername, zval *filterparams, int persistent TSRMLS_DC)
+{
+	php_lzf_filter_state *inst;
+
+	inst = pemalloc(sizeof(php_lzf_filter_state), persistent);
+	if (inst == NULL)
+		return NULL;
+
+	if (php_lzf_filter_state_ctor(inst, persistent) != SUCCESS) {
+		pefree(inst, persistent);
+		return NULL;
+	}
+
+	return php_stream_filter_alloc(&lzf_compress_ops, inst, persistent);
+}
+
+static php_stream_filter *lzf_decompress_filter_create(const char *filtername, zval *filterparams, int persistent TSRMLS_DC)
+{
+	php_lzf_filter_state *inst;
+
+	inst = pemalloc(sizeof(php_lzf_filter_state), persistent);
+	if (inst == NULL)
+		return NULL;
+
+	if (php_lzf_filter_state_ctor(inst, persistent) != SUCCESS) {
+		pefree(inst, persistent);
+		return NULL;
+	}
+
+	return php_stream_filter_alloc(&lzf_decompress_ops, inst, persistent);
+}
+
+php_stream_filter_factory php_lzf_compress_filter_factory = {
+	lzf_compress_filter_create
+};
+
+php_stream_filter_factory php_lzf_decompress_filter_factory = {
+	lzf_decompress_filter_create
+};