misc/libphysfs/archiver_hog.c
branchphysfslayer
changeset 8524 a65e9bcf0a03
parent 8522 1853628ae285
child 12213 bb5522e88ab2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libphysfs/archiver_hog.c	Fri Feb 22 05:43:56 2013 +0100
@@ -0,0 +1,116 @@
+/*
+ * HOG support routines for PhysicsFS.
+ *
+ * This driver handles Descent I/II HOG archives.
+ *
+ * The format is very simple:
+ *
+ *   The file always starts with the 3-byte signature "DHF" (Descent
+ *   HOG file). After that the files of a HOG are just attached after
+ *   another, divided by a 17 bytes header, which specifies the name
+ *   and length (in bytes) of the forthcoming file! So you just read
+ *   the header with its information of how big the following file is,
+ *   and then skip exact that number of bytes to get to the next file
+ *   in that HOG.
+ *
+ *    char sig[3] = {'D', 'H', 'F'}; // "DHF"=Descent HOG File
+ *
+ *    struct {
+ *     char file_name[13]; // Filename, padded to 13 bytes with 0s
+ *     int file_size; // filesize in bytes
+ *     char data[file_size]; // The file data
+ *    } FILE_STRUCT; // Repeated until the end of the file.
+ *
+ * (That info is from http://www.descent2.com/ddn/specs/hog/)
+ *
+ * Please see the file LICENSE.txt in the source's root directory.
+ *
+ *  This file written by Bradley Bell.
+ *  Based on grp.c by Ryan C. Gordon.
+ */
+
+#define __PHYSICSFS_INTERNAL__
+#include "physfs_internal.h"
+
+#if PHYSFS_SUPPORTS_HOG
+
+static UNPKentry *hogLoadEntries(PHYSFS_Io *io, PHYSFS_uint32 *_entCount)
+{
+    const PHYSFS_uint64 iolen = io->length(io);
+    PHYSFS_uint32 entCount = 0;
+    void *ptr = NULL;
+    UNPKentry *entries = NULL;
+    UNPKentry *entry = NULL;
+    PHYSFS_uint32 size = 0;
+    PHYSFS_uint32 pos = 3;
+
+    while (pos < iolen)
+    {
+        entCount++;
+        ptr = allocator.Realloc(ptr, sizeof (UNPKentry) * entCount);
+        GOTO_IF_MACRO(ptr == NULL, PHYSFS_ERR_OUT_OF_MEMORY, failed);
+        entries = (UNPKentry *) ptr;
+        entry = &entries[entCount-1];
+
+        GOTO_IF_MACRO(!__PHYSFS_readAll(io, &entry->name, 13), ERRPASS, failed);
+        pos += 13;
+        GOTO_IF_MACRO(!__PHYSFS_readAll(io, &size, 4), ERRPASS, failed);
+        pos += 4;
+
+        entry->size = PHYSFS_swapULE32(size);
+        entry->startPos = pos;
+        pos += size;
+
+        /* skip over entry */
+        GOTO_IF_MACRO(!io->seek(io, pos), ERRPASS, failed);
+    } /* while */
+
+    *_entCount = entCount;
+    return entries;
+
+failed:
+    allocator.Free(entries);
+    return NULL;
+} /* hogLoadEntries */
+
+
+static void *HOG_openArchive(PHYSFS_Io *io, const char *name, int forWriting)
+{
+    PHYSFS_uint8 buf[3];
+    PHYSFS_uint32 count = 0;
+    UNPKentry *entries = NULL;
+
+    assert(io != NULL);  /* shouldn't ever happen. */
+    BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
+    BAIL_IF_MACRO(!__PHYSFS_readAll(io, buf, 3), ERRPASS, NULL);
+    BAIL_IF_MACRO(memcmp(buf, "DHF", 3) != 0, PHYSFS_ERR_UNSUPPORTED, NULL);
+
+    entries = hogLoadEntries(io, &count);
+    BAIL_IF_MACRO(!entries, ERRPASS, NULL);
+    return UNPK_openArchive(io, entries, count);
+} /* HOG_openArchive */
+
+
+const PHYSFS_Archiver __PHYSFS_Archiver_HOG =
+{
+    {
+        "HOG",
+        "Descent I/II HOG file format",
+        "Bradley Bell <btb@icculus.org>",
+        "http://icculus.org/physfs/",
+    },
+    HOG_openArchive,         /* openArchive() method    */
+    UNPK_enumerateFiles,     /* enumerateFiles() method */
+    UNPK_openRead,           /* openRead() method       */
+    UNPK_openWrite,          /* openWrite() method      */
+    UNPK_openAppend,         /* openAppend() method     */
+    UNPK_remove,             /* remove() method         */
+    UNPK_mkdir,              /* mkdir() method          */
+    UNPK_closeArchive,       /* closeArchive() method   */
+    UNPK_stat                /* stat() method           */
+};
+
+#endif  /* defined PHYSFS_SUPPORTS_HOG */
+
+/* end of hog.c ... */
+