1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #import "NSData+GRPC.h" 20 21 #include <grpc/byte_buffer.h> 22 #include <grpc/byte_buffer_reader.h> 23 #include <string.h> 24 25 // TODO(jcanizales): Move these two incantations to the C library. 26 27 static void MallocAndCopyByteBufferToCharArray(grpc_byte_buffer *buffer, size_t *length, 28 char **array) { 29 grpc_byte_buffer_reader reader; 30 if (!grpc_byte_buffer_reader_init(&reader, buffer)) { 31 // grpc_byte_buffer_reader_init can fail if the data sent by the server 32 // could not be decompressed for any reason. This is an issue with the data 33 // coming from the server and thus we want the RPC to fail with error code 34 // INTERNAL. 35 *array = NULL; 36 *length = 0; 37 return; 38 } 39 // The slice contains uncompressed data even if compressed data was received 40 // because the reader takes care of automatically decompressing it 41 grpc_slice slice = grpc_byte_buffer_reader_readall(&reader); 42 size_t uncompressed_length = GRPC_SLICE_LENGTH(slice); 43 char *result = malloc(uncompressed_length); 44 if (result) { 45 memcpy(result, GRPC_SLICE_START_PTR(slice), uncompressed_length); 46 } 47 grpc_slice_unref(slice); 48 *array = result; 49 *length = uncompressed_length; 50 51 grpc_byte_buffer_reader_destroy(&reader); 52 } 53 54 static grpc_byte_buffer *CopyCharArrayToNewByteBuffer(const char *array, size_t length) { 55 grpc_slice slice = grpc_slice_from_copied_buffer(array, length); 56 grpc_byte_buffer *buffer = grpc_raw_byte_buffer_create(&slice, 1); 57 grpc_slice_unref(slice); 58 return buffer; 59 } 60 61 @implementation NSData (GRPC) 62 + (instancetype)grpc_dataWithByteBuffer:(grpc_byte_buffer *)buffer { 63 if (buffer == NULL) { 64 return nil; 65 } 66 char *array; 67 size_t length; 68 MallocAndCopyByteBufferToCharArray(buffer, &length, &array); 69 if (!array) { 70 // TODO(jcanizales): grpc_byte_buffer is reference-counted, so we can 71 // prevent this memory problem by implementing a subclass of NSData 72 // that wraps the grpc_byte_buffer. Then enumerateByteRangesUsingBlock: 73 // can be implemented using a grpc_byte_buffer_reader. 74 return nil; 75 } 76 // Not depending upon size assumption of NSUInteger 77 NSUInteger length_max = MIN(length, UINT_MAX); 78 return [self dataWithBytesNoCopy:array length:length_max freeWhenDone:YES]; 79 } 80 81 - (grpc_byte_buffer *)grpc_byteBuffer { 82 // Some implementations of NSData, as well as grpc_byte_buffer, support O(1) 83 // appending of byte arrays by not using internally a single contiguous memory 84 // block for representation. 85 // The following implementation is thus not optimal, sometimes requiring two 86 // copies (one by self.bytes and another by grpc_slice_from_copied_buffer). 87 // If it turns out to be an issue, we can use enumerateByteRangesUsingblock: 88 // to create an array of grpc_slice objects to pass to 89 // grpc_raw_byte_buffer_create. 90 // That would make it do exactly one copy, always. 91 return CopyCharArrayToNewByteBuffer((const char *)self.bytes, (size_t)self.length); 92 } 93 @end 94
