liblbx: Move extraction outside of the library.

We now use the much more general approach of supporting basic I/O
operations on files in the archives.

diff --git a/src/lbx.c b/src/lbx.c
index ff1914e8d916250bf779181c8f679e67c2fee02c..44508abe80a5976ad2c1dfdad5ae8447d75badea 100644 (file)
--- a/src/lbx.c
+++ b/src/lbx.c
@@ -45,10 +45,18 @@ struct lbx_state {
        int (*dtor)(void *handle);
        void *f;
 
+       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])
 {
        unsigned short nfiles  = unpack_16_le(hdr+0);
@@ -137,64 +145,113 @@ 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)
 {
-       unsigned char buf[1024];
-       size_t rc, written = 0;
+       int rc = 0;
 
-       assert(lbx->f);
+       if (lbx && lbx->dtor)
+               rc = lbx->dtor(lbx->f);
+       free(lbx);
+
+       return rc;
+}
 
-       if (lbx->fops->seek(lbx->f, base, SEEK_SET) != 0) {
+struct lbx_file_state *lbx_file_open(struct lbx_state *lbx, unsigned fileno)
+{
+       struct lbx_file_state *state;
+
+       if (fileno >= lbx->nfiles) {
+               lbx_errno = LBX_ERANGE;
+               return NULL;
+       }
+
+       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)

diff --git a/src/lbx.h b/src/lbx.h
index a788318bda0381840f958b83ca3d8e3de747f6b0..329bf09feb289d5c77653fcf8cbc6415a06bfb6e 100644 (file)
--- a/src/lbx.h
+++ b/src/lbx.h
@@ -33,6 +33,7 @@ extern const struct lbx_file_ops lbx_pipe_fops;
 
 /* Opaque */
 typedef struct lbx_state LBX;
+typedef struct lbx_file_state LBXfile;
 
 struct lbx_statbuf {
        const char *name;
@@ -48,8 +49,14 @@ int    lbx_close(LBX *);
 size_t lbx_numfiles(LBX *);
 
 /* File operations */
-int    lbx_stat(LBX *, size_t, struct lbx_statbuf *);
-size_t lbx_extract(LBX *, size_t, FILE *);
+int      lbx_stat(LBX *, size_t, struct lbx_statbuf *);
+
+LBXfile *lbx_file_open(LBX *lbx, unsigned fileno);
+size_t   lbx_file_read(LBXfile *f, void *buf, size_t n);
+int      lbx_file_seek(LBXfile *f, long offset, int whence);
+long     lbx_file_tell(LBXfile *f);
+int      lbx_file_eof(LBXfile *f);
+void     lbx_file_close(LBXfile *f);
 
 /* Misc operations */
 const char *lbx_strerror(void);

diff --git a/src/lbxtool.c b/src/lbxtool.c
index ec0f1b877498ba7499f7ea80c31f480ebb3bd2a3..9f0097a7f87243a24012b98e995ddd4e6d3897cc 100644 (file)
--- a/src/lbxtool.c
+++ b/src/lbxtool.c
@@ -20,6 +20,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 #include <getopt.h>
 #include <fnmatch.h>
 
@@ -99,6 +100,49 @@ int list(LBX *lbx, const char *name, int verbose, char **argv) {
        return EXIT_SUCCESS;
 }
 
+int extract_file(LBXfile *f, const struct lbx_statbuf *stat)
+{
+       int ret = -1;
+       size_t rc;
+       FILE *of;
+
+       of = fopen(stat->name, "wb");
+       if (!of) {
+               errmsg("%s: fopen: %s\n",
+                       stat->name, strerror(errno));
+               return -1;
+       }
+
+       while (1) {
+               unsigned char buf[1024];
+
+               rc = lbx_file_read(f, buf, sizeof buf);
+               if (rc == 0) {
+                       if (lbx_file_eof(f))
+                               ret = 0;
+                       break;
+               }
+
+               if (fwrite(buf, rc, 1, of) != 1) {
+                       errmsg("%s: fwrite: %s\n", stat->name, strerror(errno));
+                       break;
+               }
+
+               if (rc < sizeof buf) {
+                       if (lbx_file_eof(f))
+                               ret = 0;
+                       break;
+               }
+       }
+
+       if (fclose(of) == EOF) {
+               errmsg("%s: fclose: %s\n", stat->name, strerror(errno));
+               return -1;
+       }
+
+       return ret;
+}
+
 int extract(LBX *lbx, const char *name, int verbose, char **argv) {
        size_t nfiles;
        unsigned int i;
@@ -110,9 +154,7 @@ int extract(LBX *lbx, const char *name, int verbose, char **argv) {
 
        for (i = 0; i < nfiles; i++) {
                struct lbx_statbuf stat;
-               size_t rc;
-               FILE *of;
-               int j;
+               LBXfile *file;
 
                lbx_stat(lbx, i, &stat);
 
@@ -122,22 +164,16 @@ int extract(LBX *lbx, const char *name, int verbose, char **argv) {
                default: return EXIT_FAILURE;
                }
 
-               of = fopen(stat.name, "wbx");
-               if (!of) {
-                       errmsg("failed to create output file %s: %m.\n",
-                                                            stat.name);
-                       return EXIT_FAILURE;
+               file = lbx_file_open(lbx, i);
+               if (!file) {
+                       errmsg("failed to open archive member %s: %s.\n",
+                               stat.name, lbx_strerror());
+                       continue;
                }
 
-               if (verbose) printf("extracting %s...\n", stat.name);
-               rc = lbx_extract(lbx, i, of);
-               if (rc < stat.size) {
-                       if (rc == 0) remove(stat.name);
-                       errmsg("error extracting %s: %s.\n",
-                              stat.name, lbx_strerror());
+               if (extract_file(file, &stat) == -1)
                        return EXIT_FAILURE;
-               }
-               if (verbose) printf("wrote %zu bytes.\n", rc);
+               lbx_file_close(file);
        }
 
        return EXIT_SUCCESS;