/*
* 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