lib/sstring-old.c

   1 /* sstring.h - Declaration of "static strings" functions */
   2
   3 #define COMPILING_SSTRING
   4 #include "sstring.h"
   5
   6 #include "../core/hooks.h"
   7 #include "../core/nsmalloc.h"
   8 #include "../core/error.h"
   9
  10 #include <stdio.h>
  11
  12 #include <assert.h>
  13 #include <stdlib.h>
  14 #define _GNU_SOURCE
  15 #include <string.h>
  16
  17 /* List of free stuff */
  18 sstring *freelist[SSTRING_MAXLEN+1];
  19
  20 /* Global variables to track allocated memory */
  21 sstring *structmem;
  22 char *stringmem;
  23 int structfree;
  24 int stringfree;
  25
  26 /* Statistics counters */
  27 int getcalls;
  28 int freecalls;
  29 int allocstruct;
  30 int allocstring;
  31
  32 /* Internal function */
  33 void sstringstats(int hooknum, void *arg);
  34
  35 void initsstring() {
  36   int i;
  37   for(i=0;i<=SSTRING_MAXLEN;i++)
  38     freelist[i]=NULL;
  39
  40   structfree=0;
  41   stringfree=0;
  42   structmem=NULL;
  43   stringmem=NULL;
  44
  45   /* Initialise statistics counters */
  46   getcalls=0;
  47   freecalls=0;
  48   allocstruct=0;
  49   allocstring=0;
  50
  51   registerhook(HOOK_CORE_STATSREQUEST,&sstringstats);
  52 }
  53
  54 void finisstring() {
  55   nsfreeall(POOL_SSTRING);
  56 }
  57
  58 sstring *getsstring(const char *inputstr, int maxlen) {
  59   int i;
  60   sstring *retval=NULL;
  61   int length;
  62
  63
  64   /* getsstring() on a NULL pointer returns a NULL sstring.. */
  65   if (inputstr==NULL) {
  66     return NULL;
  67   }
  68
  69   if (inputstr[0]=='\0') {
  70     return NULL;
  71   }
  72
  73   /* Only count calls that actually did something */
  74   getcalls++;
  75
  76   length=strlen(inputstr)+1;
  77   if (length>maxlen) {
  78     length=maxlen+1;
  79   }
  80   assert(length<=SSTRING_MAXLEN);
  81
  82   /* Check to see if an approximately correct
  83    * sized string is available */
  84   for(i=0;i<SSTRING_SLACK;i++) {
  85     if (length+i>SSTRING_MAXLEN)
  86       break;
  87
  88     if (freelist[length+i]!=NULL) {
  89       retval=freelist[length+i];
  90       freelist[length+i]=retval->u.next;
  91       retval->u.l.alloc=(length+i);
  92       break;
  93     }
  94   }
  95
  96   /* None found, allocate a new one */
  97   if (retval==NULL) {
  98 getstruct:
  99     if (structfree < sizeof(sstring)) {
 100       /* We always allocate an exact multiple of these.
 101        * Therefore, if there is enough for a partial structure we broke something */
 102       assert(structfree==0);
 103
 104       /* Allocate more RAM */
 105       allocstruct++;
 106       structmem=(sstring *)nsmalloc(POOL_SSTRING,SSTRING_STRUCTALLOC);
 107       assert(structmem!=NULL);
 108       structfree=SSTRING_STRUCTALLOC;
 109     }
 110
 111     retval=structmem;
 112     structmem++;
 113     structfree-=sizeof(sstring);
 114
 115     if (stringfree < length) {
 116       /* Not enough left for what we want.
 117        * Allocate the remainder of our chunk (if any)
 118        * to something and immediately free it.
 119        * Decrement the freecalls counter to fix the stats */
 120       if (stringfree > 0) {
 121         retval->content=stringmem;
 122         retval->u.l.alloc=stringfree;
 123         stringfree=0;
 124         freecalls--;
 125         freesstring(retval);
 126
 127         /* GOTO GOTO GOTO: We need to allocate
 128          * another new struct here. Goto is the cleanest
 129          * way to do this */
 130         goto getstruct;
 131       } else {
 132         /* Grab some more string space */
 133         allocstring++;
 134         stringmem=(char *)nsmalloc(POOL_SSTRING,SSTRING_DATAALLOC);
 135         assert(stringmem!=NULL);
 136         stringfree=SSTRING_DATAALLOC;
 137       }
 138     }
 139
 140     retval->content=stringmem;
 141     retval->u.l.alloc=length;
 142     stringfree-=length;
 143     stringmem+=length;
 144   }
 145
 146   /*
 147    * At this point, retval points to a valid structure which is at
 148    * least the right size and has the "alloc" value set correctly
 149    */
 150
 151   retval->u.l.length=(length-1);
 152   strncpy(retval->content,inputstr,(length-1));
 153   retval->content[length-1]='\0';
 154
 155   return retval;
 156 }
 157
 158 void freesstring(sstring *inval) {
 159   int alloc;
 160
 161   /* Allow people to call this with a NULL value */
 162   if (inval==NULL)
 163     return;
 164
 165   /* Only count calls that actually did something */
 166   freecalls++;
 167
 168   alloc=inval->u.l.alloc;
 169   assert(alloc<=SSTRING_MAXLEN);
 170   inval->u.next=freelist[alloc];
 171   freelist[alloc]=inval;
 172 }
 173
 174 void sstringstats(int hooknum, void *arg) {
 175   char buf[512];
 176   int i,j;
 177   sstring *ssp;
 178   long statslev=(long)arg;
 179
 180   if (statslev>10) {
 181     for(i=0,j=0;i<=SSTRING_MAXLEN;i++) {
 182       for(ssp=freelist[i];ssp;ssp=ssp->u.next)
 183         j++;
 184     }
 185
 186     snprintf(buf,512,"SString : %7d get calls, %7d free calls, %7d struct allocs, %7d string allocs, %7d strings free",getcalls,freecalls,allocstruct,allocstring,j);
 187     triggerhook(HOOK_CORE_STATSREPLY,(void *)buf);
 188   }
 189 }