X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/97ae1755d995159117c16a9410f696b936d3d4f0..c02dcc9610e66ebe6154e60dcd2f109c90eb09df:/src/lbx.c

diff --git a/src/lbx.c b/src/lbx.c
index 3eac708..0e26315 100644
--- a/src/lbx.c
+++ b/src/lbx.c
@@ -1,88 +1,188 @@
+/*
+ *  2ooM: The Master of Orion II Reverse Engineering Project
+ *  Library for working with LBX archive files.
+ *  Copyright (C) 2006-2010 Nick Bowler
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifdef HAVE_CONFIG_H
+#	include "config.h"
+#endif
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdint.h>
 #include <errno.h>
+#include <assert.h>
 
-#include "byteorder.h"
+#include "pack.h"
+#include "misc.h"
 #include "lbx.h"
 
-#define LBX_MAGIC 0x0000fead
-#define MIN(a,b) (((a)<(b))?(a):(b))
+#define LBX_MAGIC    0x0000fead
+#define LBX_HDR_SIZE 8
 
 int lbx_errno = 0;
 
 struct lbx_state {
-	const char *name;
+	char *name;
 
-	FILE *f;
-	long foff;
+	const struct lbx_file_ops *fops;
+	int (*dtor)(void *handle);
+	void *f;
 
-	uint16_t nfiles;
-	uint32_t offsets[];
-};
+	struct lbx_file_state *last_file;
 
-struct lbx_state *lbx_fopen(FILE *f, const char *name)
-{
-	struct lbx_state *new = NULL;
-	uint16_t nfiles, version;
-	uint32_t magic;
+	unsigned short nfiles;
+	unsigned long offsets[];
+};
 
-	if (fread(&nfiles,  sizeof nfiles,  1, f) != 1) goto readerr;
-	if (fread(&magic,   sizeof magic,   1, f) != 1) goto readerr;
-	if (fread(&version, sizeof version, 1, f) != 1) goto readerr;
+struct lbx_file_state {
+	unsigned long base, limit, offset;
+	struct lbx_state *lbx;
+	int eof;
+};
 
-	nfiles  = letohs(nfiles);
-	magic   = letohl(magic);
-	version = letohs(version);
+static struct lbx_state *lbx_init(unsigned char hdr[static LBX_HDR_SIZE])
+{
+	unsigned short nfiles  = unpack_16_le(hdr+0);
+	unsigned long  magic   = unpack_32_le(hdr+2);
+	unsigned short version = unpack_16_le(hdr+6);
+	struct lbx_state *lbx;
 
 	if (magic != LBX_MAGIC) {
-		lbx_errno = LBX_EMAGIC;
+		lbx_errno = -LBX_EMAGIC;
 		return NULL;
 	}
-	
-	new = malloc(sizeof *new + (nfiles+1)*(sizeof *new->offsets));
-	if (!new) {
+
+	lbx = malloc(sizeof *lbx + sizeof lbx->offsets[0] * (nfiles+1));
+	if (!lbx) {
 		lbx_errno = -errno;
 		return NULL;
 	}
-	
-	*new = (struct lbx_state){
-		.name   = name,
+
+	*lbx = (struct lbx_state) {
 		.nfiles = nfiles,
-		.f      = f,
-		.foff   = sizeof nfiles + sizeof magic + sizeof version,
 	};
-	
-	if (fread(new->offsets, sizeof *new->offsets, nfiles+1, f) != nfiles+1)
-		goto readerr;
-	new->foff += sizeof *new->offsets * (nfiles+1);
-
-	return new;
-readerr:
-	if (feof(f)) {
-		lbx_errno = LBX_EEOF;
-	} else {
+
+	return lbx;
+}
+
+static char *str_dup(const char *s)
+{
+	char *buf;
+
+	buf = malloc(strlen(s)+1);
+	if (buf)
+		strcpy(buf, s);
+	return buf;
+}
+
+struct lbx_state *lbx_open(void *f, const struct lbx_file_ops *fops,
+                           int (*destructor)(void *), const char *name)
+{
+	unsigned char hdr_buf[LBX_HDR_SIZE];
+	struct lbx_state *lbx = NULL;
+	char *dupname = NULL;
+
+	dupname = str_dup(name);
+	if (!dupname) {
+		lbx_errno = -errno;
+		goto err;
+	}
+
+	if (fops->read(hdr_buf, sizeof hdr_buf, f) != sizeof hdr_buf) {
 		lbx_errno = -errno;
+		goto err;
 	}
 
-	free(new);
+	lbx = lbx_init(hdr_buf);
+	if (!lbx)
+		goto err;
+
+	lbx->name = dupname;
+	lbx->dtor = destructor;
+	lbx->fops = fops;
+	lbx->f    = f;
+
+	for (unsigned i = 0; i <= lbx->nfiles; i++) {
+		unsigned char buf[4];
+
+		if (fops->read(buf, sizeof buf, f) != sizeof buf) {
+			lbx_errno = -errno;
+			if (fops->eof(f))
+				lbx_errno = LBX_EEOF;
+			goto err;
+		}
+
+		lbx->offsets[i] = unpack_32_le(buf);
+	}
+
+	return lbx;
+err:
+	free(dupname);
+	free(lbx);
 	return NULL;
 }
 
-struct lbx_state *lbx_open(const char *path)
+static int file_close(void *f)
+{
+	return fclose((FILE *)f);
+}
+
+static int pipe_close(void *f)
 {
-	struct lbx_state *new = NULL;
+	struct lbx_pipe_state *p = f;
+	int rc;
+
+	rc = fclose(p->f);
+	free(p);
+	return rc;
+}
+
+static char *last_component(const char *name)
+{
+	char *c;
+
+	/* TODO: Handle other path separators. */
+	c = strrchr(name, '/');
+	if (!c)
+		return (char *)name;
+	return c+1;
+}
+
+struct lbx_state *lbx_fopen(const char *file)
+{
+	const char *name = last_component(file);
+	struct lbx_pipe_state *p;
 	FILE *f;
-	
-	if ((f = fopen(path, "rb"))) {
-		const char *name = strrchr(path, '/');
-		new = lbx_fopen(f, name ? name+1 : path);
-	} else {
-		lbx_errno = -errno;
+
+	f = fopen(file, "rb");
+	if (!f)
+		return NULL;
+
+	if (fseek(f, 0, SEEK_CUR) == 0)
+		return lbx_open(f, &lbx_default_fops, file_close, name);
+
+	p = malloc(sizeof *p);
+	if (!p) {
+		fclose(f);
+		return NULL;
 	}
 
-	return new;
+	*p = (struct lbx_pipe_state) { .f = f };
+	return lbx_open(p, &lbx_pipe_fops, pipe_close, name);
 }
 
 size_t lbx_numfiles(struct lbx_state *lbx)
@@ -90,110 +190,133 @@ size_t lbx_numfiles(struct lbx_state *lbx)
 	return lbx->nfiles;
 }
 
-int lbx_stat(struct lbx_state *lbx, size_t index, struct lbx_statbuf *buf)
+int
+lbx_file_stat(struct lbx_state *lbx, unsigned fileno, struct lbx_statbuf *buf)
 {
 	static char str[256]; /* FIXME */
 
-	if (index >= lbx->nfiles) {
+	if (fileno >= lbx->nfiles) {
 		buf->name = NULL;
 		lbx_errno = LBX_ERANGE;
 		return -1;
 	}
 
-	snprintf(str, sizeof str, "%s.%03d", lbx->name, index);
+	snprintf(str, sizeof str, "%s.%03u", lbx->name, fileno);
 	buf->name = str;
-	buf->size = lbx->offsets[index+1] - lbx->offsets[index];
+	buf->size = lbx->offsets[fileno+1] - lbx->offsets[fileno];
 	return 0;
 }
 
-/*
- * Read and discard len bytes from the file.  On success, returns 0.  On
- * failure, returns -1 and sets lbx_errno.
- */
-static int skipdata(FILE *f, size_t len)
+int lbx_close(struct lbx_state *lbx)
 {
-	unsigned char buf[1024];
-	
-	while (len) {
-		if (fread(buf, MIN(sizeof buf, len), 1, f) != 1) {
-			if (feof(f)) {
-				lbx_errno = LBX_EEOF;
-			} else {
-				lbx_errno = -errno;
-			}
-			return -1;
-		}
-		len -= MIN(sizeof buf, len);
-	}
+	int rc = 0;
 
-	return 0;
+	if (lbx && lbx->dtor)
+		rc = lbx->dtor(lbx->f);
+	free(lbx->name);
+	free(lbx);
+
+	return rc;
 }
 
-size_t lbx_extract(struct lbx_state *lbx, size_t index, FILE *of)
+struct lbx_file_state *lbx_file_open(struct lbx_state *lbx, unsigned fileno)
 {
-	unsigned char buf[1024];
-	size_t rc, written = 0, base, len;
+	struct lbx_file_state *state;
 
-	if (index >= lbx->nfiles) {
+	if (fileno >= lbx->nfiles) {
 		lbx_errno = LBX_ERANGE;
-		return 0;
+		return NULL;
 	}
-	
-	base = lbx->offsets[index];
-	len  = lbx->offsets[index+1] - lbx->offsets[index];
-
-	/* Seek to the beginning of the file. */
-	if (lbx->foff != base) {
-		int seekrc;
-		long dist = (lbx->foff < base) ?  (base - lbx->foff)
-		                               : -(lbx->foff - base);
-
-		seekrc = fseek(lbx->f, dist, SEEK_CUR);
-		if (seekrc == -1 && lbx->foff < base) {
-			if (skipdata(lbx->f, dist) == -1) {
-				/* lbx_errno set by skipdata */
-				return 0;
-			}
-		} else if (seekrc == -1) {
-			lbx_errno = -errno;
+
+	lbx->last_file = NULL;
+	if (lbx->fops->seek(lbx->f, lbx->offsets[fileno], SEEK_SET) != 0) {
+		lbx_errno = -errno;
+		return NULL;
+	}
+
+	state = malloc(sizeof *state);
+	if (!state) {
+		lbx_errno = -errno;
+		return NULL;
+	}
+
+	*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_file_read(struct lbx_file_state *f, void *buf, size_t n)
+{
+	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;
-		}
-		lbx->foff += dist; /* FIXME: failed skipdata breaks this. */
+		f->lbx->last_file = f;
 	}
 
-	/* Copy file data */
-	while (len) {
-		size_t amt = MIN(sizeof buf, len);
+	rc = fops->read(buf, want, f->lbx->f);
+	f->offset += rc;
 
-		rc = fread(buf, 1, amt, lbx->f);
-		lbx->foff += rc;
-		len -= rc;
-		if (rc < amt) {
-			if (feof(lbx->f)) {
-				lbx_errno = LBX_EEOF;
-			} else {
-				lbx_errno = -errno;
-			}
-			break;
-		}
+	if (want < n || (rc < want && fops->eof(f->lbx->f)))
+		f->eof = 1;
+	return rc;
+}
 
-		rc = fwrite(buf, 1, amt, of);
-		written += rc;
-		if (rc < amt) {
-			lbx_errno = -errno;
-			break;
-		}
+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;
 	}
 
-	return written;
+	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->offset = pos;
+	f->lbx->last_file = f;
+	f->eof = 0;
+
+	return 0;
 }
 
-void lbx_close(struct lbx_state *lbx)
+long lbx_file_tell(struct lbx_file_state *f)
 {
-	if (!lbx) return;
+	return f->offset;
+}
 
-	fclose(lbx->f);
-	free(lbx);
+int lbx_file_eof(struct lbx_file_state *f)
+{
+	return f->eof;
+}
+
+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)
@@ -206,6 +329,7 @@ const char *lbx_strerror(void)
 	case LBX_EMAGIC:   return "Bad magic number";
 	case LBX_EEOF:     return "Unexpected end-of-file";
 	case LBX_ERANGE:   return "Index out of range";
+	case LBX_EFORMAT:  return "Invalid file format";
 	}
 
 	return "Unknown error";