lcn_istream.h

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/* Copyright 2005 The Apache Software Foundation or its licensors, as
 * applicable.
 *
 * 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 lcn_istream.h
 * @brief Routines for manipulating read-only streams of data
 */

#ifndef _LCN_ISTREAM_H
#define _LCN_ISTREAM_H

#include "lcn_types.h"

#include <apr_file_io.h>

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

/** Opaque structure representing a stream of data. */
typedef struct lcn_istream_t lcn_istream_t;

/** Return a memory backed istream containing @a length bytes of data from
 * @a buffer, the stream is allocated from @a pool.
 */
lcn_istream_t *
lcn_ram_istream_create (const char *buffer,
                        apr_size_t length,
                        apr_pool_t *pool);

/** Return a file backed istream that wraps @a file, allocated from @a pool. */
lcn_istream_t *
lcn_file_istream_create (apr_file_t *file, apr_pool_t *pool);

/** Read a single byte from @a stream into @a byte, using @a pool for any
 * allocation.
 */
lcn_error_t *
lcn_istream_read_byte (lcn_istream_t *stream,
                       char *byte,
                       apr_pool_t *pool);

/** Read @a len bytes from @a stream into @a buffer, using @a pool for any
 * allocation
 */
lcn_error_t *
lcn_istream_read_bytes (lcn_istream_t *stream,
                        char *buffer,
                        apr_size_t len,
                        apr_pool_t *pool);

/** Read a 32 bit integer from @a stream into @a i, using @a pool for any
 * allocation
 */
lcn_error_t *
lcn_istream_read_int (lcn_istream_t *stream,
                      apr_uint32_t *i,
                      apr_pool_t *pool);

/** Read a variable length 32 bit integer from @a steam into @a i, using
 * @a pool for any allocation.
 */
lcn_error_t *
lcn_istream_read_vint (lcn_istream_t *stream,
                       apr_uint32_t *i,
                       apr_pool_t *pool);

/** Read a 64 bit integer from @a stream into @a l, using @a pool for any
 * allocation.
 */
lcn_error_t *
lcn_istream_read_long (lcn_istream_t *stream,
                       apr_uint64_t *l,
                       apr_pool_t *pool);

/** Read a variable length 64 bit integer from @a stream into @a l, using
 * @a pool for any allocation.
 */
lcn_error_t *
lcn_istream_read_vlong (lcn_istream_t *stream,
                        apr_uint64_t *l,
                        apr_pool_t *pool);

/** Read a string from @a stream into @a str, allocated from @a pool. */
lcn_error_t *
lcn_istream_read_string (lcn_istream_t *stream,
                         lcn_char_t **str,
                         apr_pool_t *pool);

/** Read @a length chars from @a stream, returning them in @a buffer, using
 * @a pool for allocation. */
lcn_error_t *
lcn_istream_read_chars (lcn_istream_t *stream,
                        lcn_char_t **buffer,
                        apr_size_t length,
                        apr_pool_t *pool);

/** Seek @a stream to @a offset, using @a pool for temporary allocations. */
lcn_error_t *
lcn_istream_seek (lcn_istream_t *stream, apr_off_t offset, apr_pool_t *pool);

/** Close @a stream, using @a pool for temporary allocations. */
lcn_error_t *
lcn_istream_close (lcn_istream_t *stream, apr_pool_t *pool);

/** Return the length of @a stream in @a length, using @a pool for temporary
 * allocations.
 */
lcn_error_t *
lcn_istream_length (lcn_istream_t *stream,
                    apr_size_t *length,
                    apr_pool_t *pool);

/** Return the current position of @a stream in @a offset, using @a pool for
 * temporary allocations.
 */
lcn_error_t *
lcn_istream_offset (lcn_istream_t *stream,
                    apr_off_t *offset,
                    apr_pool_t *pool);

/** Return a duplicate of @a source in @a dest, allocated within @a pool. */
lcn_error_t *
lcn_istream_duplicate (lcn_istream_t **dest,
                       lcn_istream_t *source,
                       apr_pool_t *pool);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif

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