Merge remote-tracking branch 'upstream/master'

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