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Diffstat (limited to 'libparc/parc/algol/parc_BufferChunker.h')
| -rwxr-xr-x | libparc/parc/algol/parc_BufferChunker.h | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/libparc/parc/algol/parc_BufferChunker.h b/libparc/parc/algol/parc_BufferChunker.h new file mode 100755 index 00000000..16f21c49 --- /dev/null +++ b/libparc/parc/algol/parc_BufferChunker.h @@ -0,0 +1,217 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * 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. + */ + +/** + * @file parc_BufferChunker.h + * @ingroup ContentObject + * @brief A BufferChunker is a chunker that segments a PARCBuffer. + * + */ + +#ifndef libparc_parc_BufferChunker_h +#define libparc_parc_BufferChunker_h + +#include <parc/algol/parc_Chunker.h> + +struct parc_buffer_chunker; +/** + * @typedef PARCChunker + * @brief The PARC Chunker + */ +typedef struct parc_buffer_chunker PARCBufferChunker; + +/** + * The mapping of a `PARCBufferChunker` to the generic `PARCChunker`. + */ +extern PARCChunkerInterface *PARCBufferChunkerAsChunker; + +/** + * Create a new chunker to segment data contained in a `PARCBuffer.` + * + * @param [in] data A `PARCBuffer` which contains the data. + * @param [in] chunkSize The size per chunk. + * + * @retval PARCChunker A newly allocated `PARCChunker` + * @retval NULL An error occurred. + * + * Example + * @code + * { + * PARCBuffer *dataToChunk = ... + * PARCChunker *chunker = ccnxChunker_CreateFromBuffer(dataToChunk, 32); + * } + */ +PARCBufferChunker *parcBufferChunker_Create(PARCBuffer *data, size_t chunkSize); + +/** + * Increase the number of references to a `PARCChunker` instance. + * + * Note that new `PARCChunker` is not created, + * only that the given `PARCChunker` reference count is incremented. + * Discard the reference by invoking {@link ccnxChunker_Release}. + * + * @param [in] chunker A pointer to the original `PARCChunker`. + * @return The value of the input parameter @p chunker. + * + * Example: + * @code + * { + * PARCBufferChunker *original = parcBufferChunker_Create(...); + * + * PARCBufferChunker *reference = parcBufferChunker_Acquire(original); + * + * parcBufferChunker_Release(&original); + * parcBufferChunker_Release(&reference); + * } + * @endcode + * + * @see parcBufferChunker_Release + */ +PARCBufferChunker *parcBufferChunker_Acquire(const PARCBufferChunker *chunker); + +/** + * Release a previously acquired reference to the specified instance, + * decrementing the reference count for the instance. + * + * The pointer to the instance is set to NULL as a side-effect of this function. + * + * If the invocation causes the last reference to the instance to be released, + * the instance is deallocated and the instance's implementation will perform + * additional cleanup and release other privately held references. + * + * @param [in,out] chunkerP A pointer to a pointer to the instance to release. + * + * + * Example: + * @code + * { + * ... + * + * PARCBufferChunker *chunker = parcBufferChunker_Acquire(instance); + * + * parcBufferChunker_Release(&chunker); + * } + * @endcode + */ +void parcBufferChunker_Release(PARCBufferChunker **chunkerP); + +/** + * Determine if two `PARCBufferChunker` instances are equal. + * + * The following equivalence relations on non-null `PARCBufferChunker` instances are maintained: + * + * * It is reflexive: for any non-null reference value x, `parcBufferChunker_Equals(x, x)` + * must return true. + * + * * It is symmetric: for any non-null reference values x and y, + * `parcBufferChunker_Equals(x, y)` must return true if and only if + * `parcBufferChunker_Equals(y, x)` returns true. + * + * * It is transitive: for any non-null reference values x, y, and z, if + * `parcBufferChunker_Equals(x, y)` returns true and + * `parcBufferChunker_Equals(y, z)` returns true, + * then `parcBufferChunker_Equals(x, z)` must return true. + * + * * It is consistent: for any non-null reference values x and y, multiple + * invocations of `parcBufferChunker_Equals(x, y)` consistently return true or + * consistently return false. + * + * * For any non-null reference value x, `parcBufferChunker_Equals(x, NULL)` must + * return false. + * + * @param chunkerA A pointer to a `PARCBufferChunker` instance. + * @param chunkerB A pointer to a `PARCBufferChunker` instance. + * @return true if the two `PARCBufferChunker` instances are equal. + * + * Example: + * @code + * { + * PARCBuffer *dataToChunk = ... + * PARCBufferChunker *chunkerA = parcBufferChunker_Create(dataToChunk, 32); + * PARCBufferChunker *chunkerB = parcBufferChunker_Create(dataToChunk, 32); + * + * bool equals = parcBufferChunker_Equals(chunkerA, chunkerB); + * } + * @endcode + */ +bool parcBufferChunker_Equals(const PARCBufferChunker *chunkerA, const PARCBufferChunker *chunkerB); + +/** + * Return an iterator to traverse the chunks of the underlying data in sequential order. + * + * This function can only be called once per chunker instance since the iterator + * will mutate internal state of the chunker. + * + * @param [in] chunker A `PARCBufferChunker` instance. + * + * @return a `PARCIterator` that traverses the chunks of the underlying data. + * + * Example + * @code + * { + * PARCBuffer *dataToChunk = ... + * PARCBufferChunker *chunker = parcBufferChunker_Create(dataToChunk, 32); + * + * PARCIterator *itr = parcBufferChunker_ForwardIterator(chunker); + * + * // use the iterator to traverse the chunker + * } + * @endcode + */ +PARCIterator *parcBufferChunker_ForwardIterator(const PARCBufferChunker *chunker); + +/** + * Return an iterator to traverse the chunks of the underlying data in sequential order. + * + * This function can only be called once per chunker instance since the iterator + * will mutate internal state of the chunker. + * + * @param [in] chunker A `PARCBufferChunker` instance. + * + * @return a `PARCIterator` that traverses the chunks of the underlying data. + * + * Example + * @code + * { + * PARCBuffer *dataToChunk = ... + * PARCBufferChunker *chunker = parcBufferChunker_Create(dataToChunk, 32); + * + * PARCIterator *itr = parcBufferChunker_ReverseIterator(chunker); + * + * // use the iterator to traverse the chunker + * } + * @endcode + */ +PARCIterator *parcBufferChunker_ReverseIterator(const PARCBufferChunker *chunker); + +/** + * Get the chunk size of a `PARCBufferChunker.` + * + * @param [in] chunker A `PARCBufferChunker` instance. + * + * @return the chunk size + * + * Example + * @code + * { + * PARCBuffer *dataToChunk = ... + * PARCBufferChunker *chunker = ... + * + * size_t chunkSize = parcBufferChunker_GetChunkSize(chunker); + * } + * @endcode + */ +size_t parcBufferChunker_GetChunkSize(const PARCBufferChunker *chunker); +#endif // libparc_parc_BufferChunker_h |