docs/rmr_support.3.rst

 
 
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============================================================================================ 
Man Page: rmr_support 
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RMR Library Functions 
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NAME 
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RMR support functions 
 
SYNOPSIS 
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:: 
  
 #include <rmr/rmr.h>
 #include <rmr/ring_inline.h>
 char* rmr_fib( char* fname );
 int rmr_has_str( char const* buf, char const* str, char sep, int max );
 int rmr_tokenise( char* buf, char** tokens, int max, char sep );
 void* rmr_mk_ring( int size );
 void rmr_ring_free( void* vr );
 static inline void* rmr_ring_extract( void* vr )
 static inline int rmr_ring_insert( void* vr, void* new_data )
 
 
 
DESCRIPTION 
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These functions support the RMR library, and are made 
available to user applications as some (e.g. route table 
generators) might need and/or want to make use of them. The 
rmr_fib function accepts a file name and reads the entire 
file into a single buffer. The intent is to provide an easy 
way to load a static route table without a lot of buffered 
I/O hoops. 
 
The rmr_has_str function accepts a *buffer* containing a set 
of delimited tokens (e.g. foo,bar,goo) and returns true if 
the target string, *str,* matches one of the tokens. The 
*sep* parameter provides the separation character in the 
buffer (e.g a comma) and *max* indicates the maximum number 
of tokens to split the buffer into before checking. 
 
The rmr_tokenise function is a simple tokeniser which splits 
*buf* into tokens at each occurrence of *sep*. Multiple 
occurrences of the separator character (e.g. a,,b) result in 
a nil token. Pointers to the tokens are placed into the 
*tokens* array provided by the caller which is assumed to 
have at least enough space for *max* entries. 
 
The rmr_mk_ring function creates a buffer ring with *size* 
entries. 
 
The rmr_ring_free function accepts a pointer to a ring 
context and frees the associated memory. 
 
The rmr_ring_insert and rmr_ring_extract functions are 
provided as static inline functions via the 
*rmr/ring_inline.h* header file. These functions both accept 
the ring *context* returned by mk_ring, and either insert a 
pointer at the next available slot (tail) or extract the data 
at the head. 
 
RETURN VALUES 
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The following are the return values for each of these 
functions. 
 
The rmr_fib function returns a pointer to the buffer 
containing the contents of the file. The buffer is terminated 
with a single nil character (0) making it a legitimate C 
string. If the file was empty or nonexistent, a buffer with 
an immediate nil character. If it is important to the calling 
programme to know if the file was empty or did not exist, the 
caller should use the system stat function call to make that 
determination. 
 
The rmr_has_str function returns 1 if *buf* contains the 
token referenced by &ita and false (0) if it does not. On 
error, a -1 value is returned and errno is set accordingly. 
 
The rmr_tokenise function returns the actual number of token 
pointers placed into *tokens* 
 
The rmr_mk_ring function returns a void pointer which is the 
*context* for the ring. 
 
The rmr_ring_insert function returns 1 if the data was 
successfully inserted into the ring, and 0 if the ring is 
full and the pointer could not be deposited. 
 
The rmr_ring_extract will return the data which is at the 
head of the ring, or NULL if the ring is empty. 
 
ERRORS 
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Not many of these functions set the value in errno, however 
the value may be one of the following: 
 
 
INVAL 
   
  Parameter(s) passed to the function were not valid. 
 
 
EXAMPLE 
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SEE ALSO 
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rmr_alloc_msg(3), rmr_call(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),