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/*
*
* Copyright 2015, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#import "NSData+GRPC.h"
#include <grpc/byte_buffer.h>
#include <grpc/byte_buffer_reader.h>
#include <string.h>
// TODO(jcanizales): Move these two incantations to the C library.
static void MallocAndCopyByteBufferToCharArray(grpc_byte_buffer *buffer,
size_t *length, char **array) {
grpc_byte_buffer_reader reader;
if (!grpc_byte_buffer_reader_init(&reader, buffer)) {
// grpc_byte_buffer_reader_init can fail if the data sent by the server
// could not be decompressed for any reason. This is an issue with the data
// coming from the server and thus we want the RPC to fail with error code
// INTERNAL.
*array = NULL;
*length = 0;
return;
}
// The slice contains uncompressed data even if compressed data was received
// because the reader takes care of automatically decompressing it
gpr_slice slice = grpc_byte_buffer_reader_readall(&reader);
size_t uncompressed_length = GPR_SLICE_LENGTH(slice);
char *result = malloc(uncompressed_length);
if (result) {
memcpy(result, GPR_SLICE_START_PTR(slice), uncompressed_length);
}
gpr_slice_unref(slice);
*array = result;
*length = uncompressed_length;
}
static grpc_byte_buffer *CopyCharArrayToNewByteBuffer(const char *array,
size_t length) {
gpr_slice slice = gpr_slice_from_copied_buffer(array, length);
grpc_byte_buffer *buffer = grpc_raw_byte_buffer_create(&slice, 1);
gpr_slice_unref(slice);
return buffer;
}
@implementation NSData (GRPC)
+ (instancetype)grpc_dataWithByteBuffer:(grpc_byte_buffer *)buffer {
if (buffer == NULL) {
return nil;
}
char *array;
size_t length;
MallocAndCopyByteBufferToCharArray(buffer, &length, &array);
if (!array) {
// TODO(jcanizales): grpc_byte_buffer is reference-counted, so we can
// prevent this memory problem by implementing a subclass of NSData
// that wraps the grpc_byte_buffer. Then enumerateByteRangesUsingBlock:
// can be implemented using a grpc_byte_buffer_reader.
return nil;
}
// Not depending upon size assumption of NSUInteger
NSUInteger length_max = MIN(length, UINT_MAX);
return [self dataWithBytesNoCopy:array length:length_max freeWhenDone:YES];
}
- (grpc_byte_buffer *)grpc_byteBuffer {
// Some implementations of NSData, as well as grpc_byte_buffer, support O(1)
// appending of byte arrays by not using internally a single contiguous memory
// block for representation.
// The following implementation is thus not optimal, sometimes requiring two
// copies (one by self.bytes and another by gpr_slice_from_copied_buffer).
// If it turns out to be an issue, we can use enumerateByteRangesUsingblock:
// to create an array of gpr_slice objects to pass to
// grpc_raw_byte_buffer_create.
// That would make it do exactly one copy, always.
return CopyCharArrayToNewByteBuffer((const char *)self.bytes,
(size_t)self.length);
}
@end
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