diff options
Diffstat (limited to 'jam-files/engine/hcache.c')
| -rw-r--r-- | jam-files/engine/hcache.c | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/jam-files/engine/hcache.c b/jam-files/engine/hcache.c new file mode 100644 index 00000000..70bb798c --- /dev/null +++ b/jam-files/engine/hcache.c @@ -0,0 +1,434 @@ +/* + * This file has been donated to Jam. + */ + +# include "jam.h" +# include "lists.h" +# include "parse.h" +# include "rules.h" +# include "regexp.h" +# include "headers.h" +# include "newstr.h" +# include "hash.h" +# include "hcache.h" +# include "variable.h" +# include "search.h" + +#ifdef OPT_HEADER_CACHE_EXT + +/* + * Craig W. McPheeters, Alias|Wavefront. + * + * hcache.c hcache.h - handle cacheing of #includes in source files. + * + * Create a cache of files scanned for headers. When starting jam, look for the + * cache file and load it if present. When finished the binding phase, create a + * new header cache. The cache contains files, their timestamps and the header + * files found in their scan. During the binding phase of jam, look in the + * header cache first for the headers contained in a file. If the cache is + * present and valid, use its contents. This results in dramatic speedups with + * large projects (eg. 3min -> 1min startup for one project.) + * + * External routines: + * hcache_init() - read and parse the local .jamdeps file. + * hcache_done() - write a new .jamdeps file. + * hcache() - return list of headers on target. Use cache or do a scan. + * + * The dependency file format is an ASCII file with 1 line per target. Each line + * has the following fields: + * @boundname@ timestamp @file@ @file@ @file@ ... \n + */ + +typedef struct hcachedata HCACHEDATA ; + +struct hcachedata +{ + char * boundname; + time_t time; + LIST * includes; + LIST * hdrscan; /* the HDRSCAN value for this target */ + int age; /* if too old, we'll remove it from cache */ + HCACHEDATA * next; +}; + + +static struct hash * hcachehash = 0; +static HCACHEDATA * hcachelist = 0; + +static int queries = 0; +static int hits = 0; + +#define CACHE_FILE_VERSION "version 4" +#define CACHE_RECORD_HEADER "header" +#define CACHE_RECORD_END "end" + + +/* + * Return the name of the header cache file. May return NULL. + * + * The user sets this by setting the HCACHEFILE variable in a Jamfile. We cache + * the result so the user can not change the cache file during header scanning. + */ + +static char * cache_name( void ) +{ + static char * name = 0; + if ( !name ) + { + LIST * hcachevar = var_get( "HCACHEFILE" ); + + if ( hcachevar ) + { + TARGET * t = bindtarget( hcachevar->string ); + + pushsettings( t->settings ); + /* Do not expect the cache file to be generated, so pass 0 as the + * third argument to search. Expect the location to be specified via + * LOCATE, so pass 0 as the fourth arugment. + */ + t->boundname = search( t->name, &t->time, 0, 0 ); + popsettings( t->settings ); + + if ( hcachevar ) + name = copystr( t->boundname ); + } + } + return name; +} + + +/* + * Return the maximum age a cache entry can have before it is purged ftom the + * cache. + */ + +static int cache_maxage( void ) +{ + int age = 100; + LIST * var = var_get( "HCACHEMAXAGE" ); + if ( var ) + { + age = atoi( var->string ); + if ( age < 0 ) + age = 0; + } + return age; +} + + +/* + * Read a netstring. The caveat is that the string can not contain ASCII 0. The + * returned value is as returned by newstr(), so it need not be freed. + */ + +char * read_netstring( FILE * f ) +{ + unsigned long len; + static char * buf = NULL; + static unsigned long buf_len = 0; + + if ( fscanf( f, " %9lu", &len ) != 1 ) + return NULL; + if ( fgetc( f ) != (int)'\t' ) + return NULL; + + if ( len > 1024 * 64 ) + return NULL; /* sanity check */ + + if ( len > buf_len ) + { + unsigned long new_len = buf_len * 2; + if ( new_len < len ) + new_len = len; + buf = (char *)BJAM_REALLOC( buf, new_len + 1 ); + if ( buf ) + buf_len = new_len; + } + + if ( !buf ) + return NULL; + + if ( fread( buf, 1, len, f ) != len ) + return NULL; + if ( fgetc( f ) != (int)'\n' ) + return NULL; + + buf[ len ] = 0; + return newstr( buf ); +} + + +/* + * Write a netstring. + */ + +void write_netstring( FILE * f, char const * s ) +{ + if ( !s ) + s = ""; + fprintf( f, "%lu\t%s\n", (long unsigned)strlen( s ), s ); +} + + +void hcache_init() +{ + HCACHEDATA cachedata; + HCACHEDATA * c; + FILE * f; + char * version; + int header_count = 0; + char * hcachename; + + hcachehash = hashinit( sizeof( HCACHEDATA ), "hcache" ); + + if ( !( hcachename = cache_name() ) ) + return; + + if ( !( f = fopen( hcachename, "rb" ) ) ) + return; + + version = read_netstring( f ); + if ( !version || strcmp( version, CACHE_FILE_VERSION ) ) + { + fclose( f ); + return; + } + + while ( 1 ) + { + char * record_type; + char * time_str; + char * age_str; + char * includes_count_str; + char * hdrscan_count_str; + int i; + int count; + LIST * l; + + record_type = read_netstring( f ); + if ( !record_type ) + { + fprintf( stderr, "invalid %s\n", hcachename ); + goto bail; + } + if ( !strcmp( record_type, CACHE_RECORD_END ) ) + break; + if ( strcmp( record_type, CACHE_RECORD_HEADER ) ) + { + fprintf( stderr, "invalid %s with record separator <%s>\n", + hcachename, record_type ? record_type : "<null>" ); + goto bail; + } + + c = &cachedata; + + c->boundname = read_netstring( f ); + time_str = read_netstring( f ); + age_str = read_netstring( f ); + includes_count_str = read_netstring( f ); + + if ( !c->boundname || !time_str || !age_str || !includes_count_str ) + { + fprintf( stderr, "invalid %s\n", hcachename ); + goto bail; + } + + c->time = atoi( time_str ); + c->age = atoi( age_str ) + 1; + + count = atoi( includes_count_str ); + for ( l = 0, i = 0; i < count; ++i ) + { + char * s = read_netstring( f ); + if ( !s ) + { + fprintf( stderr, "invalid %s\n", hcachename ); + goto bail; + } + l = list_new( l, s ); + } + c->includes = l; + + hdrscan_count_str = read_netstring( f ); + if ( !includes_count_str ) + { + list_free( c->includes ); + fprintf( stderr, "invalid %s\n", hcachename ); + goto bail; + } + + count = atoi( hdrscan_count_str ); + for ( l = 0, i = 0; i < count; ++i ) + { + char * s = read_netstring( f ); + if ( !s ) + { + fprintf( stderr, "invalid %s\n", hcachename ); + goto bail; + } + l = list_new( l, s ); + } + c->hdrscan = l; + + if ( !hashenter( hcachehash, (HASHDATA * *)&c ) ) + { + fprintf( stderr, "can't insert header cache item, bailing on %s\n", + hcachename ); + goto bail; + } + + c->next = hcachelist; + hcachelist = c; + + ++header_count; + } + + if ( DEBUG_HEADER ) + printf( "hcache read from file %s\n", hcachename ); + + bail: + fclose( f ); +} + + +void hcache_done() +{ + FILE * f; + HCACHEDATA * c; + int header_count = 0; + char * hcachename; + int maxage; + + if ( !hcachehash ) + return; + + if ( !( hcachename = cache_name() ) ) + return; + + if ( !( f = fopen( hcachename, "wb" ) ) ) + return; + + maxage = cache_maxage(); + + /* Print out the version. */ + write_netstring( f, CACHE_FILE_VERSION ); + + c = hcachelist; + for ( c = hcachelist; c; c = c->next ) + { + LIST * l; + char time_str[ 30 ]; + char age_str[ 30 ]; + char includes_count_str[ 30 ]; + char hdrscan_count_str[ 30 ]; + + if ( maxage == 0 ) + c->age = 0; + else if ( c->age > maxage ) + continue; + + sprintf( includes_count_str, "%lu", (long unsigned) list_length( c->includes ) ); + sprintf( hdrscan_count_str, "%lu", (long unsigned) list_length( c->hdrscan ) ); + sprintf( time_str, "%lu", (long unsigned) c->time ); + sprintf( age_str, "%lu", (long unsigned) c->age ); + + write_netstring( f, CACHE_RECORD_HEADER ); + write_netstring( f, c->boundname ); + write_netstring( f, time_str ); + write_netstring( f, age_str ); + write_netstring( f, includes_count_str ); + for ( l = c->includes; l; l = list_next( l ) ) + write_netstring( f, l->string ); + write_netstring( f, hdrscan_count_str ); + for ( l = c->hdrscan; l; l = list_next( l ) ) + write_netstring( f, l->string ); + fputs( "\n", f ); + ++header_count; + } + write_netstring( f, CACHE_RECORD_END ); + + if ( DEBUG_HEADER ) + printf( "hcache written to %s. %d dependencies, %.0f%% hit rate\n", + hcachename, header_count, queries ? 100.0 * hits / queries : 0 ); + + fclose ( f ); +} + + +LIST * hcache( TARGET * t, int rec, regexp * re[], LIST * hdrscan ) +{ + HCACHEDATA cachedata; + HCACHEDATA * c = &cachedata; + + LIST * l = 0; + + ++queries; + + c->boundname = t->boundname; + + if (hashcheck (hcachehash, (HASHDATA **) &c)) + { + if (c->time == t->time) + { + LIST *l1 = hdrscan, *l2 = c->hdrscan; + while (l1 && l2) { + if (l1->string != l2->string) { + l1 = NULL; + } else { + l1 = list_next(l1); + l2 = list_next(l2); + } + } + if (l1 || l2) { + if (DEBUG_HEADER) + printf("HDRSCAN out of date in cache for %s\n", + t->boundname); + + printf("HDRSCAN out of date for %s\n", t->boundname); + printf(" real : "); + list_print(hdrscan); + printf("\n cached: "); + list_print(c->hdrscan); + printf("\n"); + + list_free(c->includes); + list_free(c->hdrscan); + c->includes = 0; + c->hdrscan = 0; + } else { + if (DEBUG_HEADER) + printf ("using header cache for %s\n", t->boundname); + c->age = 0; + ++hits; + l = list_copy (0, c->includes); + return l; + } + } else { + if (DEBUG_HEADER) + printf ("header cache out of date for %s\n", t->boundname); + list_free (c->includes); + list_free(c->hdrscan); + c->includes = 0; + c->hdrscan = 0; + } + } else { + if (hashenter (hcachehash, (HASHDATA **)&c)) { + c->boundname = newstr (c->boundname); + c->next = hcachelist; + hcachelist = c; + } + } + + /* 'c' points at the cache entry. Its out of date. */ + + l = headers1 (0, t->boundname, rec, re); + + c->time = t->time; + c->age = 0; + c->includes = list_copy (0, l); + c->hdrscan = list_copy(0, hdrscan); + + return l; +} + +#endif |