#endif
/**
 * The POOL bucket type.  This bucket represents a data that was allocated
 * from a pool.  IF this bucket is still available when the pool is cleared,
 * the data is copied on to the heap.
 */
APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_pool;
/**
 * The PIPE bucket type.  This bucket represents a pipe to another program.
 */
APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_pipe;
/**
 * The IMMORTAL bucket type.  This bucket represents a segment of data that
 * the creator is willing to take responsibility for.  The core will do
 * nothing with the data in an immortal bucket
 */
APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_immortal;
/**
 * The TRANSIENT bucket type.  This bucket represents a data allocated off
 * the stack.  When the setaside function is called, this data is copied on
 * to the heap
 */
APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_transient;
/**
 * The SOCKET bucket type.  This bucket represents a socket to another machine
 */
APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_socket;


/*  *****  Simple buckets  *****  */

/**
 * Split a simple bucket into two at the given point.  Most non-reference
 * counting buckets that allow multiple references to the same block of
 * data (eg transient and immortal) will use this as their split function
 * without any additional type-specific handling.
 * @param b The bucket to be split
 * @param point The offset of the first byte in the new bucket
 * @return APR_EINVAL if the point is not within the bucket;
 *         APR_ENOMEM if allocation failed;
 *         or APR_SUCCESS
 */
APU_DECLARE_NONSTD(apr_status_t) apr_bucket_simple_split(apr_bucket *b,
                                                         apr_size_t point);

/**
 * Copy a simple bucket.  Most non-reference-counting buckets that allow
 * multiple references to the same block of data (eg transient and immortal)
 * will use this as their copy function without any additional type-specific
 * handling.
 * @param a The bucket to copy
 * @param b Returns a pointer to the new bucket
 * @return APR_ENOMEM if allocation failed;
 *         or APR_SUCCESS
 */
APU_DECLARE_NONSTD(apr_status_t) apr_bucket_simple_copy(apr_bucket *a,
                                                        apr_bucket **b);


/*  *****  Shared, reference-counted buckets  *****  */

/**
 * Initialize a bucket containing reference-counted data that may be
 * shared. The caller must allocate the bucket if necessary and
 * initialize its type-dependent fields, and allocate and initialize
 * its own private data structure. This function should only be called
 * by type-specific bucket creation functions.
 * @param b The bucket to initialize
 * @param data A pointer to the private data structure
 *             with the reference count at the start
 * @param start The start of the data in the bucket
 *              relative to the private base pointer
 * @param length The length of the data in the bucket
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_shared_make(apr_bucket *b, void *data,
				                 apr_off_t start, 
                                                 apr_size_t length);

/**
 * Decrement the refcount of the data in the bucket. This function
 * should only be called by type-specific bucket destruction functions.
 * @param data The private data pointer from the bucket to be destroyed
 * @return TRUE or FALSE; TRUE if the reference count is now
 *         zero, indicating that the shared resource itself can
 *         be destroyed by the caller.
 */
APU_DECLARE(int) apr_bucket_shared_destroy(void *data);

/**
 * Split a bucket into two at the given point, and adjust the refcount
 * to the underlying data. Most reference-counting bucket types will
 * be able to use this function as their split function without any
 * additional type-specific handling.
 * @param b The bucket to be split
 * @param point The offset of the first byte in the new bucket
 * @return APR_EINVAL if the point is not within the bucket;
 *         APR_ENOMEM if allocation failed;
 *         or APR_SUCCESS
 */
APU_DECLARE_NONSTD(apr_status_t) apr_bucket_shared_split(apr_bucket *b,
                                                         apr_size_t point);

/**
 * Copy a refcounted bucket, incrementing the reference count. Most
 * reference-counting bucket types will be able to use this function
 * as their copy function without any additional type-specific handling.
 * @param a The bucket to copy
 * @param b Returns a pointer to the new bucket
 * @return APR_ENOMEM if allocation failed;
           or APR_SUCCESS
 */
APU_DECLARE_NONSTD(apr_status_t) apr_bucket_shared_copy(apr_bucket *a,
                                                        apr_bucket **b);


/*  *****  Functions to Create Buckets of varying types  *****  */
/*
 * Each bucket type foo has two initialization functions:
 * apr_bucket_foo_make which sets up some already-allocated memory as a
 * bucket of type foo; and apr_bucket_foo_create which allocates memory
 * for the bucket, calls apr_bucket_make_foo, and initializes the
 * bucket's list pointers. The apr_bucket_foo_make functions are used
 * inside the bucket code to change the type of buckets in place;
 * other code should call apr_bucket_foo_create. All the initialization
 * functions change nothing if they fail.
 */

/**
 * Create an End of Stream bucket.  This indicates that there is no more data
 * coming from down the filter stack.  All filters should flush at this point.
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_eos_create(apr_bucket_alloc_t *list);

/**
 * Make the bucket passed in an EOS bucket.  This indicates that there is no 
 * more data coming from down the filter stack.  All filters should flush at 
 * this point.
 * @param b The bucket to make into an EOS bucket
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_eos_make(apr_bucket *b);

/**
 * Create a flush  bucket.  This indicates that filters should flush their
 * data.  There is no guarantee that they will flush it, but this is the
 * best we can do.
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_flush_create(apr_bucket_alloc_t *list);

/**
 * Make the bucket passed in a FLUSH  bucket.  This indicates that filters 
 * should flush their data.  There is no guarantee that they will flush it, 
 * but this is the best we can do.
 * @param b The bucket to make into a FLUSH bucket
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_flush_make(apr_bucket *b);

/**
 * Create a bucket referring to long-lived data.
 * @param buf The data to insert into the bucket
 * @param nbyte The size of the data to insert.
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_immortal_create(const char *buf, 
                                                     apr_size_t nbyte,
                                                     apr_bucket_alloc_t *list);

/**
 * Make the bucket passed in a bucket refer to long-lived data
 * @param b The bucket to make into a IMMORTAL bucket
 * @param buf The data to insert into the bucket
 * @param nbyte The size of the data to insert.
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_immortal_make(apr_bucket *b, 
                                                   const char *buf, 
                                                   apr_size_t nbyte);

/**
 * Create a bucket referring to data on the stack.
 * @param buf The data to insert into the bucket
 * @param nbyte The size of the data to insert.
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_transient_create(const char *buf, 
                                                      apr_size_t nbyte,
                                                      apr_bucket_alloc_t *list);

/**
 * Make the bucket passed in a bucket refer to stack data
 * @param b The bucket to make into a TRANSIENT bucket
 * @param buf The data to insert into the bucket
 * @param nbyte The size of the data to insert.
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_transient_make(apr_bucket *b, 
                                                    const char *buf,
                                                    apr_size_t nbyte);

/**
 * Create a bucket referring to memory on the heap. If the caller asks
 * for the data to be copied, this function always allocates 4K of
 * memory so that more data can be added to the bucket without
 * requiring another allocation. Therefore not all the data may be put
 * into the bucket. If copying is not requested then the bucket takes
 * over responsibility for free()ing the memory.
 * @param buf The buffer to insert into the bucket
 * @param nbyte The size of the buffer to insert.
 * @param free_func Function to use to free the data; NULL indicates that the
 *                  bucket should make a copy of the data
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_heap_create(const char *buf, 
                                                 apr_size_t nbyte,
                                                 void (*free_func)(void *data),
                                                 apr_bucket_alloc_t *list);
/**
 * Make the bucket passed in a bucket refer to heap data
 * @param b The bucket to make into a HEAP bucket
 * @param buf The buffer to insert into the bucket
 * @param nbyte The size of the buffer to insert.
 * @param free_func Function to use to free the data; NULL indicates that the
 *                  bucket should make a copy of the data
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_heap_make(apr_bucket *b, const char *buf,
                                               apr_size_t nbyte,
                                               void (*free_func)(void *data));

/**
 * Create a bucket referring to memory allocated from a pool.
 *
 * @param buf The buffer to insert into the bucket
 * @param length The number of bytes referred to by this bucket
 * @param pool The pool the memory was allocated from
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_pool_create(const char *buf, 
                                                 apr_size_t length,
                                                 apr_pool_t *pool,
                                                 apr_bucket_alloc_t *list);

/**
 * Make the bucket passed in a bucket refer to pool data
 * @param b The bucket to make into a pool bucket
 * @param buf The buffer to insert into the bucket
 * @param length The number of bytes referred to by this bucket
 * @param pool The pool the memory was allocated from
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_pool_make(apr_bucket *b, const char *buf,
                                               apr_size_t length, 
                                               apr_pool_t *pool);

#if APR_HAS_MMAP
/**
 * Create a bucket referring to mmap()ed memory.
 * @param mm The mmap to insert into the bucket
 * @param start The offset of the first byte in the mmap
 *              that this bucket refers to
 * @param length The number of bytes referred to by this bucket
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_mmap_create(apr_mmap_t *mm, 
                                                 apr_off_t start,
                                                 apr_size_t length,
                                                 apr_bucket_alloc_t *list);

/**
 * Make the bucket passed in a bucket refer to an MMAP'ed file
 * @param b The bucket to make into a MMAP bucket
 * @param mm The mmap to insert into the bucket
 * @param start The offset of the first byte in the mmap
 *              that this bucket refers to
 * @param length The number of bytes referred to by this bucket
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_mmap_make(apr_bucket *b, apr_mmap_t *mm,
                                               apr_off_t start, 
                                               apr_size_t length);
#endif

/**
 * Create a bucket referring to a socket.
 * @param thissock The socket to put in the bucket
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_socket_create(apr_socket_t *thissock,
                                                   apr_bucket_alloc_t *list);
/**
 * Make the bucket passed in a bucket refer to a socket
 * @param b The bucket to make into a SOCKET bucket
 * @param thissock The socket to put in the bucket
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_socket_make(apr_bucket *b, 
                                                 apr_socket_t *thissock);

/**
 * Create a bucket referring to a pipe.
 * @param thispipe The pipe to put in the bucket
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_pipe_create(apr_file_t *thispipe,
                                                 apr_bucket_alloc_t *list);

/**
 * Make the bucket passed in a bucket refer to a pipe
 * @param b The bucket to make into a PIPE bucket
 * @param thispipe The pipe to put in the bucket
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_pipe_make(apr_bucket *b, 
                                               apr_file_t *thispipe);

/**
 * Create a bucket referring to a file.
 * @param fd The file to put in the bucket
 * @param offset The offset where the data of interest begins in the file
 * @param len The amount of data in the file we are interested in
 * @param p The pool into which any needed structures should be created
 *          while reading from this file bucket
 * @param list The freelist from which this bucket should be allocated
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_file_create(apr_file_t *fd,
                                                 apr_off_t offset,
                                                 apr_size_t len, 
                                                 apr_pool_t *p,
                                                 apr_bucket_alloc_t *list);

/**
 * Make the bucket passed in a bucket refer to a file
 * @param b The bucket to make into a FILE bucket
 * @param fd The file to put in the bucket
 * @param offset The offset where the data of interest begins in the file
 * @param len The amount of data in the file we are interested in
 * @param p The pool into which any needed structures should be created
 *          while reading from this file bucket
 * @return The new bucket, or NULL if allocation failed
 */
APU_DECLARE(apr_bucket *) apr_bucket_file_make(apr_bucket *b, apr_file_t *fd,
                                               apr_off_t offset,
                                               apr_size_t len, apr_pool_t *p);

/**
 * Enable or disable memory-mapping for a FILE bucket (default is enabled)
 * @param b The bucket
 * @param enabled Whether memory-mapping should be enabled
 * @return APR_SUCCESS normally, or an error code if the operation fails
 */
APU_DECLARE(apr_status_t) apr_bucket_file_enable_mmap(apr_bucket *b,
                                                      int enabled);

/** @} */
#ifdef __cplusplus
}
#endif

#endif /* !APR_BUCKETS_H */