-.. This work is licensed under a Creative Commons Attribution 4.0 International License.
-.. SPDX-License-Identifier: CC-BY-4.0
-.. CAUTION: this document is generated from source in doc/src/rtd.
-.. To make changes edit the source and recompile the document.
-.. Do NOT make changes directly to .rst or .md files.
-
-============================================================================================
-Man Page: rmr_realloc_payload
-============================================================================================
-
-
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. SPDX-License-Identifier: CC-BY-4.0
+.. CAUTION: this document is generated from source in doc/src/rtd.
+.. To make changes edit the source and recompile the document.
+.. Do NOT make changes directly to .rst or .md files.
+
+============================================================================================
+Man Page: rmr_realloc_payload
+============================================================================================
+
+
RMR LIBRARY FUNCTIONS
NAME
----
-rmr_realloc_payload
+rmr_realloc_payload
SYNOPSIS
--------
-
-::
-
- #include <rmr/rmr.h>
-
- extern rmr_mbuf_t* rmr_realloc_payload( rmr_mbuf_t* msg, int new_len, int copy, int clone );
-
+
+::
+
+ #include <rmr/rmr.h>
+
+ extern rmr_mbuf_t* rmr_realloc_payload( rmr_mbuf_t* msg, int new_len, int copy, int clone );
+
DESCRIPTION
-----------
-The ``rmr_realloc_payload`` function will return a pointer to
-an RMR message buffer struct (rmr_mbuf_t) which has a payload
-large enough to accomodate *new_len* bytes. If necessary, the
-underlying payload is reallocated, and the bytes from the
-original payload are copied if the *copy* parameter is true
-(1). If the message passed in has a payload large enough,
-there is no additional memory allocation and copying.
+The ``rmr_realloc_payload`` function will return a pointer to
+an RMR message buffer struct (rmr_mbuf_t) which has a payload
+large enough to accomodate *new_len* bytes. If necessary, the
+underlying payload is reallocated, and the bytes from the
+original payload are copied if the *copy* parameter is true
+(1). If the message passed in has a payload large enough,
+there is no additional memory allocation and copying.
Cloning The Message Buffer
--------------------------
-This function can also be used to generate a separate copy of
-the original message, with the desired payload size, without
-destroying the original message buffer or the original
-payload. A standalone copy is made only when the *clone*
-parameter is true (1). When cloning, the payload is copied to
-the cloned message **only** if the *copy* parameter is true.
+This function can also be used to generate a separate copy of
+the original message, with the desired payload size, without
+destroying the original message buffer or the original
+payload. A standalone copy is made only when the *clone*
+parameter is true (1). When cloning, the payload is copied to
+the cloned message **only** if the *copy* parameter is true.
Message Buffer Metadata
-----------------------
-The metadata in the original message buffer (message type,
-subscription ID, and payload length) will be preserved if the
-*copy* parameter is true. When this parameter is not true
-(0), then these values are set to the uninitialised value
-(-1) for type and ID, and the length is set to 0.
+The metadata in the original message buffer (message type,
+subscription ID, and payload length) will be preserved if the
+*copy* parameter is true. When this parameter is not true
+(0), then these values are set to the uninitialised value
+(-1) for type and ID, and the length is set to 0.
RETURN VALUE
------------
-The ``rmr_realloc_payload`` function returns a pointer to the
-message buffer with the payload which is large enough to hold
-*new_len* bytes. If the *clone* option is true, this will be
-a pointer to the newly cloned message buffer; the original
-message buffer pointer may still be used to reference that
-message. It is the calling application's responsibility to
-free the memory associateed with both messages using the
-rmr_free_msg() function.
-
-When the *clone* option is not used, it is still good
-practice by the calling application to capture and use this
-reference as it is possible that the message buffer, and not
-just the payload buffer, was reallocated. In the event of an
-error, a nil pointer will be returned and the value of
-*errno* will be set to reflect the problem.
+The ``rmr_realloc_payload`` function returns a pointer to the
+message buffer with the payload which is large enough to hold
+*new_len* bytes. If the *clone* option is true, this will be
+a pointer to the newly cloned message buffer; the original
+message buffer pointer may still be used to reference that
+message. It is the calling application's responsibility to
+free the memory associateed with both messages using the
+rmr_free_msg() function.
+
+When the *clone* option is not used, it is still good
+practice by the calling application to capture and use this
+reference as it is possible that the message buffer, and not
+just the payload buffer, was reallocated. In the event of an
+error, a nil pointer will be returned and the value of
+*errno* will be set to reflect the problem.
ERRORS
------
-These value of *errno* will reflect the error condition if a
-nil pointer is returned:
-
-
- .. list-table::
- :widths: auto
- :header-rows: 0
- :class: borderless
-
- * - **ENOMEM**
- -
- Memory allocation of the new payload failed.
-
- * - **EINVAL**
- -
- The pointer passed in was nil, or referenced an invalid
- message, or the required length was not valid.
-
-
+These value of *errno* will reflect the error condition if a
+nil pointer is returned:
+
+
+ .. list-table::
+ :widths: auto
+ :header-rows: 0
+ :class: borderless
+
+ * - **ENOMEM**
+ -
+ Memory allocation of the new payload failed.
+
+ * - **EINVAL**
+ -
+ The pointer passed in was nil, or referenced an invalid
+ message, or the required length was not valid.
+
+
EXAMPLE
-------
-The following code bit illustrates how this function can be
-used to reallocate a buffer for a return to sender
-acknowledgement message which is larger than the message
-received.
-
-
-::
-
- if( rmr_payload_size( msg ) < ack_sz ) { // received message too small for ack
- msg = rmr_realloc_payload( msg, ack_sz, 0, 0 ); // reallocate the message with a payload big enough
- if( msg == NULL ) {
- fprintf( stderr, "[ERR] realloc returned a nil pointer: %s\\n", strerror( errno ) );
- } else {
- // populate and send ack message
- }
- }
-
-
+The following code bit illustrates how this function can be
+used to reallocate a buffer for a return to sender
+acknowledgement message which is larger than the message
+received.
+
+
+::
+
+ if( rmr_payload_size( msg ) < ack_sz ) { // received message too small for ack
+ msg = rmr_realloc_payload( msg, ack_sz, 0, 0 ); // reallocate the message with a payload big enough
+ if( msg == NULL ) {
+ fprintf( stderr, "[ERR] realloc returned a nil pointer: %s\\n", strerror( errno ) );
+ } else {
+ // populate and send ack message
+ }
+ }
+
+
SEE ALSO
--------
-rmr_alloc_msg(3), rmr_free_msg(3), rmr_init(3),
-rmr_payload_size(3), rmr_send_msg(3), rmr_rcv_msg(3),
-rmr_rcv_specific(3), rmr_rts_msg(3), rmr_ready(3),
-rmr_fib(3), rmr_has_str(3), rmr_set_stimeout(3),
-rmr_tokenise(3), rmr_mk_ring(3), rmr_ring_free(3)
+rmr_alloc_msg(3), rmr_free_msg(3), rmr_init(3),
+rmr_payload_size(3), rmr_send_msg(3), rmr_rcv_msg(3),
+rmr_rcv_specific(3), rmr_rts_msg(3), rmr_ready(3),
+rmr_fib(3), rmr_has_str(3), rmr_set_stimeout(3),
+rmr_tokenise(3), rmr_mk_ring(3), rmr_ring_free(3)
Code Review / ric-plt / lib / rmr.git / blobdiff