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Diffstat (limited to 'libparc/parc/algol/parc_FileOutputStream.h')
-rw-r--r-- | libparc/parc/algol/parc_FileOutputStream.h | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/libparc/parc/algol/parc_FileOutputStream.h b/libparc/parc/algol/parc_FileOutputStream.h new file mode 100644 index 00000000..51251561 --- /dev/null +++ b/libparc/parc/algol/parc_FileOutputStream.h @@ -0,0 +1,142 @@ +/* + * 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_FileOutputStream.h + * @ingroup inputoutput + * @brief A file output stream is an output stream for writing data to a File or to a FileDescriptor. + * + * Whether or not a file is available or may be created depends upon the underlying platform. + * Some platforms, in particular, allow a file to be opened for writing by only one FileOutputStream + * (or other file-writing object) at a time. In such situations the constructors in this class will + * fail if the file involved is already open. + * + */ + +#ifndef libparc_parc_FileOutputStream_h +#define libparc_parc_FileOutputStream_h + +#include <parc/algol/parc_Buffer.h> +#include <parc/algol/parc_OutputStream.h> + +struct parc_file_output_stream; +typedef struct parc_file_output_stream PARCFileOutputStream; + +/** + * The mapping of a `PARCFileOutputStream` to the generic `PARCInputStream`. + * + */ +extern PARCOutputStreamInterface *PARCFileOutputStreamAsPARCOutputStream; + +/** + * Create a new output stream on a file descriptor. + * + * Caution: When the resulting `PARCFileOutputStream` is released, the file descriptor is closed. + * If you wrap STDOUT_FILENO, for example, the standard output of the application will be closed + * when this PARCFileOutputStream is released. + * To avoid this, use dup(2) or dup2(2). + * + * @param [in] fileDescriptor The fileDescriptor for the file on which to create an output stream. + * + * @return A pointer to a new instance of `PARCFileOutputStream` + * + * Example: + * @code + * { + * <#example#> + * } + * @endcode + */ +PARCFileOutputStream *parcFileOutputStream_Create(int fileDescriptor); + +/** + * Convert an instance of `PARCFileOutputStream` to a `PARCOutputStream`. + * + * @param [in] fileOutputStream A pointer to a valid PARCFileOutputStream. + * + * @return A pointer to a new instance of `PARCOutputStream`. + * + * Example: + * @code + * <#example#> + * @endcode + */ +PARCOutputStream *parcFileOutputStream_AsOutputStream(PARCFileOutputStream *fileOutputStream); + +/** + * Acquire a new reference to an instance of `PARCFileOutputStream`. + * + * The reference count to the instance is incremented. + * + * @param [in] stream The instance of `PARCFileOutputStream` to which to refer. + * + * @return The same value as the input parameter @p stream + * + * Example: + * @code + * { + * <#example#> + * } + * @endcode + */ +PARCFileOutputStream *parcFileOutputStream_Acquire(const PARCFileOutputStream *stream); + +/** + * Release a `PARCFileOutputStream` reference. + * + * Only the last invocation where the reference count is decremented to zero, + * will actually destroy the `PARCFileOutputStream`. + * + * @param [in,out] streamPtr is a pointer to the `PARCFileOutputStream` reference. + * + * Example: + * @code + * <#example#> + * @endcode + */ +void parcFileOutputStream_Release(PARCFileOutputStream **streamPtr); + +/** + * Write the contents of a {@link PARCBuffer} to the given `PARCFileOutputStream`. + * + * The contents of the `PARCBuffer` from the current position to the limit are written to the `PARCFileOutputStream`. + * When this function returns the position is set to the end of the last successfully written byte of data. + * + * @param [in,out] outputStream The `PARCOutputStream` to write to. + * @param [in] buffer The `PARCBuffer` to write, from the current position of the buffer to its limit. + * + * @return true The entire contents of the `PARCBuffer` were written. + * @return false The entire contents of the `PARCBuffer` were not written. + * + * Example: + * @code + * { + * PARCFileOutputStream *stream = + * parcFileOutputStream_Create(open("/tmp/test_parc_FileOutputStream", O_CREAT|O_WRONLY|O_TRUNC, 0600)); + * + * PARCBuffer *buffer = parcBuffer_Allocate(16 * 1024*1024); + * + * parcFileOutputStream_Write(stream, buffer); + * + * assertFalse(parcBuffer_HasRemaining(buffer), "Expected the buffer to be emtpy"); + * + * parcBuffer_Release(&buffer); + * + * parcFileOutputStream_Release(&stream); + * } + * @endcode + */ +bool parcFileOutputStream_Write(PARCFileOutputStream *outputStream, PARCBuffer *buffer); +#endif // libparc_parc_FileOutputStream_h |