X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/a6ae4dd126e7b2b678e0db31b68bba51311282cc..c72e960aaef313863ec629dc0e4b3dcbfc44b784:/src/lbx.c

diff --git a/src/lbx.c b/src/lbx.c
index 4b5d7f3..77a150a 100644
--- a/src/lbx.c
+++ b/src/lbx.c
@@ -23,13 +23,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdint.h>
 #include <errno.h>
 #include <assert.h>
 
-#include <sys/stat.h>
-#include <sys/mman.h>
-
 #include "pack.h"
 #include "misc.h"
 #include "lbx.h"
@@ -46,8 +42,16 @@ struct lbx_state {
 	int (*dtor)(void *handle);
 	void *f;
 
-	uint16_t nfiles;
-	uint32_t offsets[];
+	struct lbx_file_state *last_file;
+
+	unsigned short nfiles;
+	unsigned long offsets[];
+};
+
+struct lbx_file_state {
+	unsigned long base, limit, offset;
+	struct lbx_state *lbx;
+	int eof;
 };
 
 static struct lbx_state *lbx_init(unsigned char hdr[static LBX_HDR_SIZE])
@@ -138,64 +142,113 @@ int lbx_stat(struct lbx_state *lbx, size_t index, struct lbx_statbuf *buf)
 	return 0;
 }
 
-static size_t
-_lbx_fextract(struct lbx_state *lbx, size_t base, size_t len, FILE *of)
+int lbx_close(struct lbx_state *lbx)
+{
+	int rc = 0;
+
+	if (lbx && lbx->dtor)
+		rc = lbx->dtor(lbx->f);
+	free(lbx);
+
+	return rc;
+}
+
+struct lbx_file_state *lbx_file_open(struct lbx_state *lbx, unsigned fileno)
 {
-	unsigned char buf[1024];
-	size_t rc, written = 0;
+	struct lbx_file_state *state;
 
-	assert(lbx->f);
+	if (fileno >= lbx->nfiles) {
+		lbx_errno = LBX_ERANGE;
+		return NULL;
+	}
 
-	if (lbx->fops->seek(lbx->f, base, SEEK_SET) != 0) {
+	lbx->last_file = NULL;
+	if (lbx->fops->seek(lbx->f, lbx->offsets[fileno], SEEK_SET) != 0) {
 		lbx_errno = -errno;
-		return 0;
+		return NULL;
 	}
-	
-	while (len) {
-		size_t amt = MIN(len, sizeof buf);
-
-		rc = lbx->fops->read(buf, amt, lbx->f);
-		len -= rc;
-		if (rc < amt) {
-			if (lbx->fops->eof(lbx->f)) lbx_errno = LBX_EEOF;
-			else lbx_errno = -errno;
-			break;
-		}
 
-		rc = fwrite(buf, 1, amt, of);
-		written += rc;
-		if (rc < amt) {
-			lbx_errno = -errno;
-			break;
-		}
+	state = malloc(sizeof *state);
+	if (!state) {
+		lbx_errno = -errno;
+		return NULL;
 	}
 
-	return written;
+	*state = (struct lbx_file_state) {
+		.base  = lbx->offsets[fileno],
+		.limit = lbx->offsets[fileno+1] - lbx->offsets[fileno],
+		.lbx   = lbx,
+	};
+
+	lbx->last_file = state;
+	return state;
 }
 
-size_t lbx_extract(struct lbx_state *lbx, size_t index, FILE *of)
+size_t lbx_file_read(struct lbx_file_state *f, void *buf, size_t n)
 {
-	size_t base, len;
+	const struct lbx_file_ops *fops = f->lbx->fops;
+	size_t want = MIN(n, f->limit - f->offset);
+	size_t rc;
+
+	if (f != f->lbx->last_file) {
+		f->lbx->last_file = NULL;
+		if (fops->seek(f->lbx->f, f->base + f->limit, SEEK_SET) != 0)
+			return 0;
+		f->lbx->last_file = f;
+	}
 
-	if (index >= lbx->nfiles) {
-		lbx_errno = LBX_ERANGE;
-		return 0;
+	rc = fops->read(buf, want, f->lbx->f);
+	f->offset += rc;
+
+	if (want < n || (rc < want && fops->eof(f->lbx->f)))
+		f->eof = 1;
+	return rc;
+}
+
+int lbx_file_seek(struct lbx_file_state *f, long offset, int whence)
+{
+	const struct lbx_file_ops *fops = f->lbx->fops;
+	unsigned long pos;
+
+	switch (whence) {
+	case SEEK_CUR:
+		pos = f->offset + offset;
+		break;
+	case SEEK_SET:
+		pos = offset;
+		break;
+	case SEEK_END:
+		pos = f->limit + offset;
+		break;
 	}
-	
-	base = lbx->offsets[index];
-	len  = lbx->offsets[index+1] - lbx->offsets[index];
-	return _lbx_fextract(lbx, base, len, of);
+
+	if (pos > f->limit)
+		return -1;
+
+	f->lbx->last_file = NULL;
+	if (fops->seek(f->lbx->f, f->base + pos, SEEK_SET) != 0)
+		return -1;
+	f->lbx->last_file = f;
+	f->eof = 0;
+
+	return 0;
 }
 
-int lbx_close(struct lbx_state *lbx)
+long lbx_file_tell(struct lbx_file_state *f)
 {
-	int rc = 0;
+	return f->offset;
+}
 
-	if (lbx && lbx->dtor)
-		rc = lbx->dtor(lbx->f);
-	free(lbx);
+int lbx_file_eof(struct lbx_file_state *f)
+{
+	return f->eof;
+}
 
-	return rc;
+void lbx_file_close(struct lbx_file_state *f)
+{
+	if (f->lbx->last_file == f)
+		f->lbx->last_file = NULL;
+	free(f);
 }
 
 const char *lbx_strerror(void)