Man Page: rmr_support¶

RMR LIBRARY FUNCTIONS¶

NAME¶

RMR support functions

SYNOPSIS¶

#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¶

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¶

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¶

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.