src/hcache.c

   1 /*
   2  * This file has been donated to Jam.
   3  */
   4 int optShowHCacheStats = 0;
   5 int optShowHCacheInfo = 0;
   6
   7 //#ifdef OPT_HEADER_CACHE_EXT
   8 #include <limits.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <unistd.h>
  13
  14 #include "jam.h"
  15 #include "lists.h"
  16 #include "parse.h"
  17 #include "rules.h"
  18 #include "hsregexp.h"
  19 #include "headers.h"
  20 #include "newstr.h"
  21 #include "hash.h"
  22 #include "hcache.h"
  23 #include "variable.h"
  24 #include "search.h"
  25 #include "pathsys.h"
  26
  27
  28 /*
  29  * Craig W. McPheeters, Alias|Wavefront.
  30  *
  31  * hcache.c hcache.h - handle cacheing of #includes in source files
  32  *
  33  * Create a cache of files scanned for headers.  When starting jam,
  34  * look for the cache file and load it if present.  When finished the
  35  * binding phase, create a new header cache.  The cache contains
  36  * files, their timestamps and the header files found in their scan.
  37  * During the binding phase of jam, look in the header cache first for
  38  * the headers contained in a file.  If the cache is present and
  39  * valid, use its contents.  This results in dramatic speedups with
  40  * large projects (eg. 3min -> 1min startup for one project.)
  41  *
  42  * External routines:
  43  *    hcache_init() - read and parse the local .jamdeps file.
  44  *    hcache_done() - write a new .jamdeps file
  45  *    hcache() - return list of headers on target.  Use cache or do a scan.
  46  */
  47 typedef struct hcachedata {
  48   const char *boundname;
  49   time_t time;
  50   LIST *includes;
  51   LIST *hdrscan; /* the HDRSCAN value for this target */
  52   int age; /* if too old, we'll remove it from cache */
  53   struct hcachedata *next;
  54 } HCACHEDATA;
  55
  56
  57 static struct hash *hcachehash = NULL;
  58 static HCACHEDATA *hcachelist = NULL;
  59
  60 static int queries = 0;
  61 static int hits = 0;
  62
  63
  64 #define CACHE_FILE_VERSION   "k8jam header cache!"
  65 #define CACHE_RECORD_HEADER  "hdr"
  66 #define CACHE_RECORD_END     "end"
  67
  68
  69 /*
  70  * Return the name of the header cache file.  May return NULL.
  71  *
  72  * The user sets this by setting the HCACHEFILE variable in a Jamfile.
  73  * We cache the result so the user can't change the cache file during
  74  * header scanning.
  75  */
  76 static const char *hcacheFileName (void) {
  77   static const char *name = NULL;
  78   if (name == NULL) {
  79     LIST *hcachevar = var_get("HCACHEFILE");
  80     if (hcachevar) {
  81       TARGET *t = bindtarget(hcachevar->string);
  82       pushsettings(t->settings);
  83       t->boundname = search(t->name, &t->time);
  84       popsettings(t->settings);
  85       if (t->boundname) name = copystr(t->boundname);
  86     }
  87   }
  88   return name;
  89 }
  90
  91
  92 /*
  93  * Return the maximum age a cache entry can have before it is purged from the cache.
  94  */
  95 static int cache_maxage (void) {
  96   int age = 100;
  97   LIST *var = var_get("HCACHEMAXAGE");
  98   if (var) {
  99     age = atoi(var->string);
 100     if (age < 0) age = 0;
 101   }
 102   return age;
 103 }
 104
 105
 106 /*
 107  * read string
 108  * the returned value is as returned by newstr(), so it need not be freed
 109  */
 110 static const char *readStr (FILE *fl) {
 111   short sz;
 112   static char buf[33000];
 113   //
 114   if (fread(&sz, sizeof(sz), 1, fl) != 1) return NULL;
 115   if (sz < 0 || sz > 32700) return NULL;
 116   if (sz > 0) {
 117     if (fread(buf, sz, 1, fl) != 1) return NULL;
 118   }
 119   buf[sz] = 0;
 120   return newstr(buf);
 121 }
 122
 123
 124 /*
 125  * write string
 126  */
 127 static int writeStr (FILE *fl, const char *s) {
 128   int sz;
 129   short sx;
 130   //
 131   if (s == NULL) s = "";
 132   sz = strlen(s);
 133   if (sz > 32700) return -1;
 134   sx = sz;
 135   if (fwrite(&sx, sizeof(sx), 1, fl) != 1) return -1;
 136   if (sz > 0) {
 137     if (fwrite(s, sz, 1, fl) != 1) return -1;
 138   }
 139   return 0;
 140 }
 141
 142
 143 void hcache_init (void) {
 144   HCACHEDATA cachedata, *c;
 145   FILE *fl;
 146   const char *version, *hcachename;
 147   int header_count = 0;
 148   //
 149   hcachehash = hashinit(sizeof(HCACHEDATA), "hcache");
 150   if (!(hcachename = hcacheFileName())) return;
 151   if (!(fl = fopen(hcachename, "rb"))) return;
 152   version = readStr(fl);
 153   if (!version || strcmp(version, CACHE_FILE_VERSION)) { fclose(fl); return; }
 154   if (DEBUG_HEADER || optShowHCacheInfo) printf("HCACHE: reading cache from '%s'\n", hcachename);
 155   for (;;) {
 156     const char *record_type;
 157     int i, count;
 158     LIST *l;
 159     //
 160     record_type = readStr(fl);
 161     if (!record_type) goto bail;
 162     if (!strcmp(record_type, CACHE_RECORD_END)) break;
 163     if (strcmp(record_type, CACHE_RECORD_HEADER)) { printf("invalid %s with record separator <%s>\n", hcachename, record_type ? record_type : "<null>"); goto bail; }
 164     c = &cachedata;
 165     c->boundname = readStr(fl);
 166     if (!c->boundname) goto bail;
 167     if (fread(&c->time, sizeof(c->time), 1, fl) != 1) goto bail;
 168     if (fread(&c->age, sizeof(c->age), 1, fl) != 1) goto bail;
 169     if (fread(&count, sizeof(count), 1, fl) != 1) goto bail;
 170     //
 171     for (l = 0, i = 0; i < count; ++i) {
 172       const char *s = readStr(fl);
 173       if (!s) goto bail;
 174       l = list_new(l, s, 1);
 175     }
 176     c->includes = l;
 177     if (fread(&count, sizeof(count), 1, fl) != 1) { list_free(c->includes); goto bail; }
 178     //
 179     for (l = 0, i = 0; i < count; ++i) {
 180       const char *s = readStr(fl);
 181       if (!s) goto bail;
 182       l = list_new(l, s, 1);
 183     }
 184     c->hdrscan = l;
 185     if (!hashenter(hcachehash, (HASHDATA **)&c)) {
 186       printf("can't insert header cache item, bailing on %s\n", hcachename);
 187       goto bail;
 188     }
 189     c->next = hcachelist;
 190     hcachelist = c;
 191     ++header_count;
 192   }
 193   if (DEBUG_HEADER) printf("HCACHE: hcache read from file %s\n", hcachename);
 194   fclose(fl);
 195   return;
 196 bail:
 197   fclose(fl);
 198   printf("HCACHE: invalid cache file: '%s'\n", hcachename);
 199 }
 200
 201
 202 void hcache_done (void) {
 203   FILE *fl;
 204   HCACHEDATA *c;
 205   int header_count = 0;
 206   const char *hcachename;
 207   int maxage;
 208   //
 209   if (!hcachehash) return;
 210   if (!(hcachename = hcacheFileName())) return;
 211   if (!(fl = fopen(hcachename, "wb"))) return;
 212   maxage = cache_maxage();
 213   /* print out the version */
 214   if (writeStr(fl, CACHE_FILE_VERSION)) goto bail;
 215   c = hcachelist;
 216   for (c = hcachelist; c != NULL; c = c->next) {
 217     LIST *l;
 218     int count;
 219     //
 220     if (maxage == 0) c->age = 0;
 221     else if (c->age > maxage) continue;
 222     if (writeStr(fl, CACHE_RECORD_HEADER)) goto bail;
 223     if (writeStr(fl, c->boundname)) goto bail;
 224     if (fwrite(&c->time, sizeof(c->time), 1, fl) != 1) goto bail;
 225     if (fwrite(&c->age, sizeof(c->age), 1, fl) != 1) goto bail;
 226     count = list_length(c->includes);
 227     if (fwrite(&count, sizeof(count), 1, fl) != 1) goto bail;
 228     //
 229     for (l = c->includes; l; l = list_next(l)) {
 230       if (writeStr(fl, l->string)) goto bail;
 231     }
 232     //
 233     count = list_length(c->hdrscan);
 234     if (fwrite(&count, sizeof(count), 1, fl) != 1) goto bail;
 235     //
 236     for (l = c->hdrscan; l; l = list_next(l)) {
 237       if (writeStr(fl, l->string)) goto bail;
 238     }
 239     ++header_count;
 240   }
 241   if (writeStr(fl, CACHE_RECORD_END)) goto bail;
 242   fclose(fl);
 243   if (DEBUG_HEADER || optShowHCacheStats) printf("HCACHE: cache written to '%s'; %d dependencies, %.0f%% hit rate\n", hcachename, header_count, queries?100.0*hits/queries:0);
 244   return;
 245 bail:
 246   fclose(fl);
 247   unlink(hcachename);
 248   printf("HCACHE: can't write cache file: '%s'\n", hcachename);
 249 }
 250
 251
 252 LIST *hcache (TARGET *t, LIST *hdrscan) {
 253   HCACHEDATA cachedata, *c = &cachedata;
 254   LIST *l = 0;
 255   char _normalizedPath[PATH_MAX];
 256   char *normalizedPath = normalize_path(t->boundname, _normalizedPath, sizeof(_normalizedPath));
 257   //
 258   ++queries;
 259   c->boundname = normalizedPath!=NULL?normalizedPath:t->boundname;
 260   if (hashcheck(hcachehash, (HASHDATA **)&c)) {
 261     if (c->time == t->time) {
 262       LIST *l1 = hdrscan, *l2 = c->hdrscan;
 263       while (l1 && l2) {
 264         if (l1->string != l2->string) {
 265           l1 = NULL;
 266         } else {
 267           l1 = list_next(l1);
 268           l2 = list_next(l2);
 269         }
 270       }
 271       if (l1 || l2) {
 272         if (DEBUG_HEADER) printf("HCACHE: HDRSCAN out of date in cache for %s\n", t->boundname);
 273         /*
 274         printf("HDRSCAN out of date for %s\n", t->boundname);
 275         printf(" real  : ");
 276         list_print(hdrscan);
 277         printf("\n cached: ");
 278         list_print(c->hdrscan);
 279         printf("\n");
 280         */
 281         list_free(c->includes);
 282         list_free(c->hdrscan);
 283         c->includes = 0;
 284         c->hdrscan = 0;
 285       } else {
 286         if (DEBUG_HEADER || optShowHCacheInfo) printf("HCACHE: using header cache for %s\n", t->boundname);
 287         c->age = 0;
 288         ++hits;
 289         l = list_copy(0, c->includes);
 290         return l;
 291       }
 292     } else {
 293       if (DEBUG_HEADER || optShowHCacheInfo) printf("HCACHE: header cache out of date for %s\n", t->boundname);
 294       list_free(c->includes);
 295       list_free(c->hdrscan);
 296       c->includes = 0;
 297       c->hdrscan = 0;
 298     }
 299   } else {
 300     if (hashenter(hcachehash, (HASHDATA **)&c)) {
 301       c->boundname = newstr(c->boundname);
 302       c->next = hcachelist;
 303       hcachelist = c;
 304     }
 305   }
 306   /* 'c' points at the cache entry; its out of date */
 307   l = headers1(t->boundname, hdrscan);
 308   c->time = t->time;
 309   c->age = 0;
 310   c->includes = list_copy(0, l);
 311   c->hdrscan = list_copy(0, hdrscan);
 312   return l;
 313 }
 314
 315
 316 //#endif