X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/b42e3c4eadf05be2506e1a1f8deb2cf24064c18b..8456fd3535202bc2b79df4ddb794cbfd075054fd:/src/lbx.c

diff --git a/src/lbx.c b/src/lbx.c
index 481123b..d3815a9 100644
--- a/src/lbx.c
+++ b/src/lbx.c
@@ -1,48 +1,136 @@
+#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 <sys/stat.h>
+#include <sys/mman.h>
 
 #include "byteorder.h"
+#include "misc.h"
 #include "lbx.h"
 
 #define LBX_MAGIC 0x0000fead
 
+int lbx_errno = 0;
+
 struct lbx_state {
+	const char *name;
+
+	unsigned char *mem;
+	size_t memsize;
 	FILE *f;
+	long foff;
+
 	uint16_t nfiles;
 	uint32_t offsets[];
 };
 
-struct lbx_state *lbx_fopen(FILE *f)
+struct lbx_state *lbx_fopen(FILE *f, const char *name)
 {
 	struct lbx_state *new = NULL;
 	uint16_t nfiles, version;
 	uint32_t magic;
 
-	if (fread(&nfiles,  sizeof nfiles,  1, f) != 1) return NULL;
-	if (fread(&magic,   sizeof magic,   1, f) != 1) return NULL;
-	if (fread(&version, sizeof version, 1, f) != 1) return NULL;
+	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;
 
 	nfiles  = letohs(nfiles);
 	magic   = letohl(magic);
 	version = letohs(version);
 
-	if (magic != LBX_MAGIC)
+	if (magic != LBX_MAGIC) {
+		lbx_errno = LBX_EMAGIC;
 		return NULL;
+	}
 	
 	new = malloc(sizeof *new + (nfiles+1)*(sizeof *new->offsets));
-	if (!new)
+	if (!new) {
+		lbx_errno = -errno;
 		return NULL;
+	}
 	
 	*new = (struct lbx_state){
+		.name   = name,
 		.nfiles = nfiles,
-		.f = f,
+		.f      = f,
+		.foff   = sizeof nfiles + sizeof magic + sizeof version,
 	};
 	
 	if (fread(new->offsets, sizeof *new->offsets, nfiles+1, f) != nfiles+1)
-		return free(new), NULL;
+		goto readerr;
+	new->foff += sizeof *new->offsets * (nfiles+1);
+
+	return new;
+readerr:
+	if (feof(f)) {
+		lbx_errno = LBX_EEOF;
+	} else {
+		lbx_errno = -errno;
+	}
+
+	free(new);
+	return NULL;
+}
+
+static int _lbx_memcpy(void *dest, struct lbx_state *src, size_t size)
+{
+	if (src->foff + size > src->memsize)
+		return -1;
+	memcpy(dest, src->mem + src->foff, size);
+	src->foff += size;
+	return 0;
+}
+
+struct lbx_state *lbx_mopen(void *_mem, size_t size, const char *name)
+{
+	struct lbx_state *new = NULL;
+	struct lbx_state tmp = { .mem = _mem, .memsize = size };
+	uint16_t nfiles, version;
+	uint32_t magic;
+
+	if (_lbx_memcpy(&nfiles,  &tmp, sizeof nfiles)  == -1) goto eof;
+	if (_lbx_memcpy(&magic,   &tmp, sizeof magic)   == -1) goto eof;
+	if (_lbx_memcpy(&version, &tmp, sizeof version) == -1) goto eof;
+
+	nfiles  = letohs(nfiles);
+	magic   = letohl(magic);
+	version = letohs(version);
+
+	if (magic != LBX_MAGIC) {
+		lbx_errno = LBX_EMAGIC;
+		return NULL;
+	}
+	
+	new = malloc(sizeof *new + (nfiles+1)*(sizeof *new->offsets));
+	if (!new) {
+		lbx_errno = -errno;
+		return NULL;
+	}
+	
+	*new = (struct lbx_state){
+		.name    = name,
+		.nfiles  = nfiles,
+		.mem     = _mem,
+		.memsize = size,
+		.foff    = tmp.foff,
+	};
+	
+	if (_lbx_memcpy(new->offsets, new, (nfiles+1)*(sizeof *new->offsets)))
+		goto eof;
 
 	return new;
+eof:
+	free(new);
+	lbx_errno = LBX_EEOF;
+	return NULL;
 }
 
 struct lbx_state *lbx_open(const char *path)
@@ -50,14 +138,161 @@ struct lbx_state *lbx_open(const char *path)
 	struct lbx_state *new = NULL;
 	FILE *f;
 	
-	if ((f = fopen(path, "rb")))
-		new = lbx_fopen(f);
+	if ((f = fopen(path, "rb"))) {
+		const char *name = strrchr(path, '/');
+		new = lbx_fopen(f, name ? name+1 : path);
+	} else {
+		lbx_errno = -errno;
+	}
 
 	return new;
 }
 
+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)
+{
+	static char str[256]; /* FIXME */
+
+	if (index >= lbx->nfiles) {
+		buf->name = NULL;
+		lbx_errno = LBX_ERANGE;
+		return -1;
+	}
+
+	snprintf(str, sizeof str, "%s.%03d", lbx->name, index);
+	buf->name = str;
+	buf->size = lbx->offsets[index+1] - lbx->offsets[index];
+	return 0;
+}
+
+static size_t
+_lbx_mextract(struct lbx_state *lbx, size_t base, size_t len, FILE *of)
+{
+	size_t rc;
+
+	assert(lbx->mem);
+	assert(base + len <= lbx->memsize);
+
+	rc = fwrite(lbx->mem + base, 1, len, of);
+	if (rc < len)
+		lbx_errno = -errno;
+
+	return rc;
+}
+
+static size_t
+_lbx_fextract(struct lbx_state *lbx, size_t base, size_t len, FILE *of)
+{
+	unsigned char buf[1024];
+	size_t rc, written = 0;
+
+	assert(lbx->f);
+
+	if (_lbx_fseek(lbx->f, &lbx->foff, base) == -1)
+		return 0;
+	
+	while (len) {
+		size_t amt = MIN(len, sizeof buf);
+
+		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;
+		}
+
+		rc = fwrite(buf, 1, amt, of);
+		written += rc;
+		if (rc < amt) {
+			lbx_errno = -errno;
+			break;
+		}
+	}
+
+	return written;
+}
+
+size_t lbx_extract(struct lbx_state *lbx, size_t index, FILE *of)
+{
+	size_t base, len;
+
+	if (index >= lbx->nfiles) {
+		lbx_errno = LBX_ERANGE;
+		return 0;
+	}
+	
+	base = lbx->offsets[index];
+	len  = lbx->offsets[index+1] - lbx->offsets[index];
+
+	if (lbx->mem)
+		return _lbx_mextract(lbx, base, len, 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)
 {
-	fclose(lbx->f);
+	if (!lbx) return;
+
+	if (lbx->f) {
+		fclose(lbx->f);
+		if (lbx->mem) {
+			munmap(lbx->mem, lbx->memsize);
+		}
+	}
+
 	free(lbx);
 }
+
+const char *lbx_strerror(void)
+{
+	if (lbx_errno < 0)
+		return strerror(-lbx_errno);
+
+	switch (lbx_errno) {
+	case LBX_ESUCCESS: return "Success";
+	case LBX_EMAGIC:   return "Bad magic number";
+	case LBX_EEOF:     return "Unexpected end-of-file";
+	case LBX_ERANGE:   return "Index out of range";
+	}
+
+	return "Unknown error";
+}