.TH qlibs:constmap 3
.SH NAME
constmap \- fetch matching strings from a hashed data structure in constant time
.SH SYNTAX
.B #include \(dqconstmap.h\(dq
.SH SYNOPSIS
int \fBconstmap_init\fP(struct constmap \fI*cm\fR,char \fI*string\fR,int \fIlen\fR,int \fIflagcolon\fR);
.br
int \fBconstmap_init_char\fP(struct constmap \fI*cm\fR,char \fI*string\fR,int \fIlen\fR,int \fIflagcolon\fR,char \fIflagchar\fR);
.br
char *\fBconstmap\fP(struct constmap \fI*cm\fR,char \fI*string\fR,int \fIlen\fR);
.br
void \fBconstmap_free\fP(\fIstruct constmap *cm\fR);
.SH DESCRIPTION
Reading a file perhaps with
.I control_readfile(&cmap,"path/filename",0)
.B constmap_init 
can be used to convert its content into a constant time search map:
.IR constmap .
Here, you can specify whether the entries in
.I constmap
are plain or key/value structured setting
.I flagcolon 
to one and assuming the delimiter equals to a colon:
.IR : .
If the delimiter needs to be particulary tailored, use
.BR constmap_init_char .

Given the search 
.I string 
and providing its length
.I len 
(without the trailing \\0)
.B constmap
will now retrieve the information in constant time
returning a pointer to the search result or 
.IR 0 .

The datastructure can be freed by means of
.BR constmap_free .
.SH EXAMPLE
#include <constmap.h>

 struct constmap cmap;
 stralloc result = {0};
 char *info;
 char *search;

 if (control_readfile(&cmap,"control/conf",0))
   constmap_init(&cmap,result.s,result.len,1));
 
 info = constmap(&cmap,search,str_len (search));
 if (!info) return 0;

.SH "SEE ALSO"
cdbread(3), cdbmake(3)