/* * 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 * */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 */    struct hcachedata	*next;} ;typedef struct hcachedata HCACHEDATA ;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't 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 );        /* Don't expect cache file to be generated, so pass 0           as third argument to search. */	    t->boundname = search( t->name, &t->time, 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 * from the cache. */static intcache_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't 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. */voidwrite_netstring(FILE* f, const char* s){    if (!s)	s = "";    fprintf(f, "%lu\t%s\n", strlen(s), s);}voidhcache_init(){    HCACHEDATA  cachedata, *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, 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);}voidhcache_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", list_length(c->includes));	sprintf(hdrscan_count_str, "%lu", list_length(c->hdrscan));	sprintf(time_str, "%lu", c->time);	sprintf(age_str, "%lu", 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, *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