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/*
*
* Copyright 2015 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#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
grpc_slice slice = grpc_byte_buffer_reader_readall(&reader);
size_t uncompressed_length = GRPC_SLICE_LENGTH(slice);
char *result = malloc(uncompressed_length);
if (result) {
memcpy(result, GRPC_SLICE_START_PTR(slice), uncompressed_length);
}
grpc_slice_unref(slice);
*array = result;
*length = uncompressed_length;
grpc_byte_buffer_reader_destroy(&reader);
}
static grpc_byte_buffer *CopyCharArrayToNewByteBuffer(const char *array, size_t length) {
grpc_slice slice = grpc_slice_from_copied_buffer(array, length);
grpc_byte_buffer *buffer = grpc_raw_byte_buffer_create(&slice, 1);
grpc_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 grpc_slice_from_copied_buffer).
// If it turns out to be an issue, we can use enumerateByteRangesUsingblock:
// to create an array of grpc_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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