X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/00f5f0706e7552e86a28d9fd66df962e095e8576..8456fd3535202bc2b79df4ddb794cbfd075054fd:/src/lbx.c

diff --git a/src/lbx.c b/src/lbx.c
index 20c32e7..d3815a9 100644
--- a/src/lbx.c
+++ b/src/lbx.c
@@ -1,3 +1,7 @@
+#ifdef HAVE_CONFIG_H
+#	include "config.h"
+#endif
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -5,11 +9,14 @@
 #include <errno.h>
 #include <assert.h>
 
+#include <sys/stat.h>
+#include <sys/mman.h>
+
 #include "byteorder.h"
+#include "misc.h"
 #include "lbx.h"
 
 #define LBX_MAGIC 0x0000fead
-#define MIN(a,b) (((a)<(b))?(a):(b))
 
 int lbx_errno = 0;
 
@@ -162,43 +169,6 @@ int lbx_stat(struct lbx_state *lbx, size_t index, struct lbx_statbuf *buf)
 	return 0;
 }
 
-/* Advance to the beginning of the index'th file by either fseek or reading. */
-static int _lbx_fseek(struct lbx_state *lbx, size_t base)
-{
-	static unsigned char oblivion[1024];
-	long dist;
-
-	if (lbx->foff < base) {
-		dist = base - lbx->foff;
-	} else if (lbx->foff > base) {
-		dist = -(long)(lbx->foff - base);
-	} else {
-		return 0;
-	}
-
-	if (fseek(lbx->f, dist, SEEK_CUR) == 0) {
-		lbx->foff += dist;
-	} else if (lbx->foff < base) {
-		while (dist) {
-			size_t rc, amt = MIN(sizeof oblivion, dist);
-			rc = fread(oblivion, 1, amt, lbx->f);
-			lbx->foff += rc;
-			dist -= rc;
-			if (rc < amt) {
-				if (feof(lbx->f))
-					lbx_errno = LBX_EEOF;
-				else
-					lbx_errno = -errno;
-				return -1;
-			}
-		}
-	} else {
-		lbx_errno = -errno;
-		return -1;
-	}
-	return 0;
-}
-
 static size_t
 _lbx_mextract(struct lbx_state *lbx, size_t base, size_t len, FILE *of)
 {
@@ -222,7 +192,7 @@ _lbx_fextract(struct lbx_state *lbx, size_t base, size_t len, FILE *of)
 
 	assert(lbx->f);
 
-	if (_lbx_fseek(lbx, base) == -1)
+	if (_lbx_fseek(lbx->f, &lbx->foff, base) == -1)
 		return 0;
 	
 	while (len) {
@@ -265,12 +235,50 @@ size_t lbx_extract(struct lbx_state *lbx, size_t index, FILE *of)
 	return _lbx_fextract(lbx, base, len, of);
 }
 
+void *lbx_mmap(struct lbx_state *lbx, size_t index, size_t *len)
+{
+	unsigned char *mapping;
+	struct stat statbuf;
+	size_t base;
+
+	if (index >= lbx->nfiles) {
+		lbx_errno = LBX_ERANGE;
+		return NULL;
+	}
+	
+	base = lbx->offsets[index];
+	*len = lbx->offsets[index+1] - lbx->offsets[index];
+
+	if (lbx->mem)
+		return lbx->mem + base;
+	
+	if (fstat(fileno(lbx->f), &statbuf) == -1) {
+		lbx_errno = -errno;
+		return NULL;
+	}
+
+	mapping = mmap(NULL, statbuf.st_size, PROT_READ, 0, fileno(lbx->f), 0);
+	if (mapping == MAP_FAILED) {
+		lbx_errno = -errno;
+		return NULL;
+	}
+
+	lbx->mem     = mapping;
+	lbx->memsize = statbuf.st_size;
+	return mapping + base;
+}
+
 void lbx_close(struct lbx_state *lbx)
 {
 	if (!lbx) return;
 
-	if (lbx->f)
+	if (lbx->f) {
 		fclose(lbx->f);
+		if (lbx->mem) {
+			munmap(lbx->mem, lbx->memsize);
+		}
+	}
+
 	free(lbx);
 }