misc/libphysfs/archiver_lzma.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_lzma.c	Fri Feb 22 05:43:56 2013 +0100
@@ -0,0 +1,701 @@
+/*
+ * LZMA support routines for PhysicsFS.
+ *
+ * Please see the file lzma.txt in the lzma/ directory.
+ *
+ *  This file was written by Dennis Schridde, with some peeking at "7zMain.c"
+ *   by Igor Pavlov.
+ */
+
+#define __PHYSICSFS_INTERNAL__
+#include "physfs_internal.h"
+
+#if PHYSFS_SUPPORTS_7Z
+
+#include "lzma/C/7zCrc.h"
+#include "lzma/C/Archive/7z/7zIn.h"
+#include "lzma/C/Archive/7z/7zExtract.h"
+
+
+/* 7z internal from 7zIn.c */
+extern int TestSignatureCandidate(Byte *testBytes);
+
+
+#ifdef _LZMA_IN_CB
+# define BUFFER_SIZE (1 << 12)
+#endif /* _LZMA_IN_CB */
+
+
+/*
+ * Carries filestream metadata through 7z
+ */
+typedef struct _FileInputStream
+{
+    ISzAlloc allocImp; /* Allocation implementation, used by 7z */
+    ISzAlloc allocTempImp; /* Temporary allocation implementation, used by 7z */
+    ISzInStream inStream; /* Input stream with read callbacks, used by 7z */
+    PHYSFS_Io *io;  /* Filehandle, used by read implementation */
+#ifdef _LZMA_IN_CB
+    Byte buffer[BUFFER_SIZE]; /* Buffer, used by read implementation */
+#endif /* _LZMA_IN_CB */
+} FileInputStream;
+
+/*
+ * In the 7z format archives are splited into blocks, those are called folders
+ * Set by LZMA_read()
+*/
+typedef struct _LZMAfolder
+{
+    PHYSFS_uint32 index; /* Index of folder in archive */
+    PHYSFS_uint32 references; /* Number of files using this block */
+    PHYSFS_uint8 *cache; /* Cached folder */
+    size_t size; /* Size of folder */
+} LZMAfolder;
+
+/*
+ * Set by LZMA_openArchive(), except folder which gets it's values
+ *  in LZMA_read()
+ */
+typedef struct _LZMAarchive
+{
+    struct _LZMAfile *files; /* Array of files, size == archive->db.Database.NumFiles */
+    LZMAfolder *folders; /* Array of folders, size == archive->db.Database.NumFolders */
+    CArchiveDatabaseEx db; /* For 7z: Database */
+    FileInputStream stream; /* For 7z: Input file incl. read and seek callbacks */
+} LZMAarchive;
+
+/* Set by LZMA_openArchive(), except offset which is set by LZMA_read() */
+typedef struct _LZMAfile
+{
+    PHYSFS_uint32 index; /* Index of file in archive */
+    LZMAarchive *archive; /* Link to corresponding archive */
+    LZMAfolder *folder; /* Link to corresponding folder */
+    CFileItem *item; /* For 7z: File info, eg. name, size */
+    size_t offset; /* Offset in folder */
+    size_t position; /* Current "virtual" position in file */
+} LZMAfile;
+
+
+/* Memory management implementations to be passed to 7z */
+
+static void *SzAllocPhysicsFS(size_t size)
+{
+    return ((size == 0) ? NULL : allocator.Malloc(size));
+} /* SzAllocPhysicsFS */
+
+
+static void SzFreePhysicsFS(void *address)
+{
+    if (address != NULL)
+        allocator.Free(address);
+} /* SzFreePhysicsFS */
+
+
+/* Filesystem implementations to be passed to 7z */
+
+#ifdef _LZMA_IN_CB
+
+/*
+ * Read implementation, to be passed to 7z
+ * WARNING: If the ISzInStream in 'object' is not contained in a valid FileInputStream this _will_ break horribly!
+ */
+SZ_RESULT SzFileReadImp(void *object, void **buffer, size_t maxReqSize,
+                        size_t *processedSize)
+{
+    FileInputStream *s = (FileInputStream *)(object - offsetof(FileInputStream, inStream)); /* HACK! */
+    PHYSFS_sint64 processedSizeLoc = 0;
+
+    if (maxReqSize > BUFFER_SIZE)
+        maxReqSize = BUFFER_SIZE;
+    processedSizeLoc = s->io->read(s->io, s->buffer, maxReqSize);
+    *buffer = s->buffer;
+    if (processedSize != NULL)
+        *processedSize = (size_t) processedSizeLoc;
+
+    return SZ_OK;
+} /* SzFileReadImp */
+
+#else
+
+/*
+ * Read implementation, to be passed to 7z
+ * WARNING: If the ISzInStream in 'object' is not contained in a valid FileInputStream this _will_ break horribly!
+ */
+SZ_RESULT SzFileReadImp(void *object, void *buffer, size_t size,
+                        size_t *processedSize)
+{
+    FileInputStream *s = (FileInputStream *)((unsigned long)object - offsetof(FileInputStream, inStream)); /* HACK! */
+    const size_t processedSizeLoc = s->io->read(s->io, buffer, size);
+    if (processedSize != NULL)
+        *processedSize = processedSizeLoc;
+    return SZ_OK;
+} /* SzFileReadImp */
+
+#endif
+
+/*
+ * Seek implementation, to be passed to 7z
+ * WARNING: If the ISzInStream in 'object' is not contained in a valid FileInputStream this _will_ break horribly!
+ */
+SZ_RESULT SzFileSeekImp(void *object, CFileSize pos)
+{
+    FileInputStream *s = (FileInputStream *)((unsigned long)object - offsetof(FileInputStream, inStream)); /* HACK! */
+    if (s->io->seek(s->io, (PHYSFS_uint64) pos))
+        return SZ_OK;
+    return SZE_FAIL;
+} /* SzFileSeekImp */
+
+
+/*
+ * Translate Microsoft FILETIME (used by 7zip) into UNIX timestamp
+ */
+static PHYSFS_sint64 lzma_filetime_to_unix_timestamp(CArchiveFileTime *ft)
+{
+    /* MS counts in nanoseconds ... */
+    const PHYSFS_uint64 FILETIME_NANOTICKS_PER_SECOND = __PHYSFS_UI64(10000000);
+    /* MS likes to count seconds since 01.01.1601 ... */
+    const PHYSFS_uint64 FILETIME_UNIX_DIFF = __PHYSFS_UI64(11644473600);
+
+    PHYSFS_uint64 filetime = ft->Low | ((PHYSFS_uint64)ft->High << 32);
+    return filetime/FILETIME_NANOTICKS_PER_SECOND - FILETIME_UNIX_DIFF;
+} /* lzma_filetime_to_unix_timestamp */
+
+
+/*
+ * Compare a file with a given name, C89 stdlib variant
+ * Used for sorting
+ */
+static int lzma_file_cmp_stdlib(const void *key, const void *object)
+{
+    const char *name = (const char *) key;
+    LZMAfile *file = (LZMAfile *) object;
+    return strcmp(name, file->item->Name);
+} /* lzma_file_cmp_posix */
+
+
+/*
+ * Compare two files with each other based on the name
+ * Used for sorting
+ */
+static int lzma_file_cmp(void *_a, size_t one, size_t two)
+{
+    LZMAfile *files = (LZMAfile *) _a;
+    return strcmp(files[one].item->Name, files[two].item->Name);
+} /* lzma_file_cmp */
+
+
+/*
+ * Swap two entries in the file array
+ */
+static void lzma_file_swap(void *_a, size_t one, size_t two)
+{
+    LZMAfile tmp;
+    LZMAfile *first = &(((LZMAfile *) _a)[one]);
+    LZMAfile *second = &(((LZMAfile *) _a)[two]);
+    memcpy(&tmp, first, sizeof (LZMAfile));
+    memcpy(first, second, sizeof (LZMAfile));
+    memcpy(second, &tmp, sizeof (LZMAfile));
+} /* lzma_file_swap */
+
+
+/*
+ * Find entry 'name' in 'archive'
+ */
+static LZMAfile * lzma_find_file(const LZMAarchive *archive, const char *name)
+{
+    LZMAfile *file = bsearch(name, archive->files, archive->db.Database.NumFiles, sizeof(*archive->files), lzma_file_cmp_stdlib); /* FIXME: Should become __PHYSFS_search!!! */
+
+    BAIL_IF_MACRO(file == NULL, PHYSFS_ERR_NO_SUCH_PATH, NULL);
+
+    return file;
+} /* lzma_find_file */
+
+
+/*
+ * Load metadata for the file at given index
+ */
+static int lzma_file_init(LZMAarchive *archive, PHYSFS_uint32 fileIndex)
+{
+    LZMAfile *file = &archive->files[fileIndex];
+    PHYSFS_uint32 folderIndex = archive->db.FileIndexToFolderIndexMap[fileIndex];
+
+    file->index = fileIndex; /* Store index into 7z array, since we sort our own. */
+    file->archive = archive;
+    file->folder = (folderIndex != (PHYSFS_uint32)-1 ? &archive->folders[folderIndex] : NULL); /* Directories don't have a folder (they contain no own data...) */
+    file->item = &archive->db.Database.Files[fileIndex]; /* Holds crucial data and is often referenced -> Store link */
+    file->position = 0;
+    file->offset = 0; /* Offset will be set by LZMA_read() */
+
+    return 1;
+} /* lzma_load_file */
+
+
+/*
+ * Load metadata for all files
+ */
+static int lzma_files_init(LZMAarchive *archive)
+{
+    PHYSFS_uint32 fileIndex = 0, numFiles = archive->db.Database.NumFiles;
+
+    for (fileIndex = 0; fileIndex < numFiles; fileIndex++ )
+    {
+        if (!lzma_file_init(archive, fileIndex))
+        {
+            return 0; /* FALSE on failure */
+        }
+    } /* for */
+
+   __PHYSFS_sort(archive->files, (size_t) numFiles, lzma_file_cmp, lzma_file_swap);
+
+    return 1;
+} /* lzma_load_files */
+
+
+/*
+ * Initialise specified archive
+ */
+static void lzma_archive_init(LZMAarchive *archive)
+{
+    memset(archive, 0, sizeof(*archive));
+
+    /* Prepare callbacks for 7z */
+    archive->stream.inStream.Read = SzFileReadImp;
+    archive->stream.inStream.Seek = SzFileSeekImp;
+
+    archive->stream.allocImp.Alloc = SzAllocPhysicsFS;
+    archive->stream.allocImp.Free = SzFreePhysicsFS;
+
+    archive->stream.allocTempImp.Alloc = SzAllocPhysicsFS;
+    archive->stream.allocTempImp.Free = SzFreePhysicsFS;
+}
+
+
+/*
+ * Deinitialise archive
+ */
+static void lzma_archive_exit(LZMAarchive *archive)
+{
+    /* Free arrays */
+    allocator.Free(archive->folders);
+    allocator.Free(archive->files);
+    allocator.Free(archive);
+}
+
+/*
+ * Wrap all 7z calls in this, so the physfs error state is set appropriately.
+ */
+static int lzma_err(SZ_RESULT rc)
+{
+    switch (rc)
+    {
+        case SZ_OK: /* Same as LZMA_RESULT_OK */
+            break;
+        case SZE_DATA_ERROR: /* Same as LZMA_RESULT_DATA_ERROR */
+            __PHYSFS_setError(PHYSFS_ERR_CORRUPT); /*!!!FIXME: was "PHYSFS_ERR_DATA_ERROR" */
+            break;
+        case SZE_OUTOFMEMORY:
+            __PHYSFS_setError(PHYSFS_ERR_OUT_OF_MEMORY);
+            break;
+        case SZE_CRC_ERROR:
+            __PHYSFS_setError(PHYSFS_ERR_CORRUPT);
+            break;
+        case SZE_NOTIMPL:
+            __PHYSFS_setError(PHYSFS_ERR_UNSUPPORTED);
+            break;
+        case SZE_FAIL:
+            __PHYSFS_setError(PHYSFS_ERR_OTHER_ERROR);  /* !!! FIXME: right? */
+            break;
+        case SZE_ARCHIVE_ERROR:
+            __PHYSFS_setError(PHYSFS_ERR_CORRUPT);  /* !!! FIXME: right? */
+            break;
+        default:
+            __PHYSFS_setError(PHYSFS_ERR_OTHER_ERROR);
+    } /* switch */
+
+    return rc;
+} /* lzma_err */
+
+
+static PHYSFS_sint64 LZMA_read(PHYSFS_Io *io, void *outBuf, PHYSFS_uint64 len)
+{
+    LZMAfile *file = (LZMAfile *) io->opaque;
+
+    size_t wantedSize = (size_t) len;
+    const size_t remainingSize = file->item->Size - file->position;
+    size_t fileSize = 0;
+
+    BAIL_IF_MACRO(wantedSize == 0, ERRPASS, 0); /* quick rejection. */
+    BAIL_IF_MACRO(remainingSize == 0, PHYSFS_ERR_PAST_EOF, 0);
+
+    if (wantedSize > remainingSize)
+        wantedSize = remainingSize;
+
+    /* Only decompress the folder if it is not already cached */
+    if (file->folder->cache == NULL)
+    {
+        const int rc = lzma_err(SzExtract(
+            &file->archive->stream.inStream, /* compressed data */
+            &file->archive->db, /* 7z's database, containing everything */
+            file->index, /* Index into database arrays */
+            /* Index of cached folder, will be changed by SzExtract */
+            &file->folder->index,
+            /* Cache for decompressed folder, allocated/freed by SzExtract */
+            &file->folder->cache,
+            /* Size of cache, will be changed by SzExtract */
+            &file->folder->size,
+            /* Offset of this file inside the cache, set by SzExtract */
+            &file->offset,
+            &fileSize, /* Size of this file */
+            &file->archive->stream.allocImp,
+            &file->archive->stream.allocTempImp));
+
+        if (rc != SZ_OK)
+            return -1;
+    } /* if */
+
+    /* Copy wanted bytes over from cache to outBuf */
+    memcpy(outBuf, (file->folder->cache + file->offset + file->position),
+            wantedSize);
+    file->position += wantedSize; /* Increase virtual position */
+
+    return wantedSize;
+} /* LZMA_read */
+
+
+static PHYSFS_sint64 LZMA_write(PHYSFS_Io *io, const void *b, PHYSFS_uint64 len)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, -1);
+} /* LZMA_write */
+
+
+static PHYSFS_sint64 LZMA_tell(PHYSFS_Io *io)
+{
+    LZMAfile *file = (LZMAfile *) io->opaque;
+    return file->position;
+} /* LZMA_tell */
+
+
+static int LZMA_seek(PHYSFS_Io *io, PHYSFS_uint64 offset)
+{
+    LZMAfile *file = (LZMAfile *) io->opaque;
+
+    BAIL_IF_MACRO(offset > file->item->Size, PHYSFS_ERR_PAST_EOF, 0);
+
+    file->position = offset; /* We only use a virtual position... */
+
+    return 1;
+} /* LZMA_seek */
+
+
+static PHYSFS_sint64 LZMA_length(PHYSFS_Io *io)
+{
+    const LZMAfile *file = (LZMAfile *) io->opaque;
+    return (file->item->Size);
+} /* LZMA_length */
+
+
+static PHYSFS_Io *LZMA_duplicate(PHYSFS_Io *_io)
+{
+    /* !!! FIXME: this archiver needs to be reworked to allow multiple
+     * !!! FIXME:  opens before we worry about duplication. */
+    BAIL_MACRO(PHYSFS_ERR_UNSUPPORTED, NULL);
+} /* LZMA_duplicate */
+
+
+static int LZMA_flush(PHYSFS_Io *io) { return 1;  /* no write support. */ }
+
+
+static void LZMA_destroy(PHYSFS_Io *io)
+{
+    LZMAfile *file = (LZMAfile *) io->opaque;
+
+    if (file->folder != NULL)
+    {
+        /* Only decrease refcount if someone actually requested this file... Prevents from overflows and close-on-open... */
+        if (file->folder->references > 0)
+            file->folder->references--;
+        if (file->folder->references == 0)
+        {
+            /* Free the cache which might have been allocated by LZMA_read() */
+            allocator.Free(file->folder->cache);
+            file->folder->cache = NULL;
+        }
+        /* !!! FIXME: we don't free (file) or (file->folder)?! */
+    } /* if */
+} /* LZMA_destroy */
+
+
+static const PHYSFS_Io LZMA_Io =
+{
+    CURRENT_PHYSFS_IO_API_VERSION, NULL,
+    LZMA_read,
+    LZMA_write,
+    LZMA_seek,
+    LZMA_tell,
+    LZMA_length,
+    LZMA_duplicate,
+    LZMA_flush,
+    LZMA_destroy
+};
+
+
+static void *LZMA_openArchive(PHYSFS_Io *io, const char *name, int forWriting)
+{
+    PHYSFS_uint8 sig[k7zSignatureSize];
+    size_t len = 0;
+    LZMAarchive *archive = NULL;
+
+    assert(io != NULL);  /* shouldn't ever happen. */
+
+    BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
+
+    if (io->read(io, sig, k7zSignatureSize) != k7zSignatureSize)
+        return 0;
+    BAIL_IF_MACRO(!TestSignatureCandidate(sig), PHYSFS_ERR_UNSUPPORTED, NULL);
+    BAIL_IF_MACRO(!io->seek(io, 0), ERRPASS, NULL);
+
+    archive = (LZMAarchive *) allocator.Malloc(sizeof (LZMAarchive));
+    BAIL_IF_MACRO(archive == NULL, PHYSFS_ERR_OUT_OF_MEMORY, NULL);
+
+    lzma_archive_init(archive);
+    archive->stream.io = io;
+
+    CrcGenerateTable();
+    SzArDbExInit(&archive->db);
+    if (lzma_err(SzArchiveOpen(&archive->stream.inStream,
+                               &archive->db,
+                               &archive->stream.allocImp,
+                               &archive->stream.allocTempImp)) != SZ_OK)
+    {
+        SzArDbExFree(&archive->db, SzFreePhysicsFS);
+        lzma_archive_exit(archive);
+        return NULL; /* Error is set by lzma_err! */
+    } /* if */
+
+    len = archive->db.Database.NumFiles * sizeof (LZMAfile);
+    archive->files = (LZMAfile *) allocator.Malloc(len);
+    if (archive->files == NULL)
+    {
+        SzArDbExFree(&archive->db, SzFreePhysicsFS);
+        lzma_archive_exit(archive);
+        BAIL_MACRO(PHYSFS_ERR_OUT_OF_MEMORY, NULL);
+    }
+
+    /*
+     * Init with 0 so we know when a folder is already cached
+     * Values will be set by LZMA_openRead()
+     */
+    memset(archive->files, 0, len);
+
+    len = archive->db.Database.NumFolders * sizeof (LZMAfolder);
+    archive->folders = (LZMAfolder *) allocator.Malloc(len);
+    if (archive->folders == NULL)
+    {
+        SzArDbExFree(&archive->db, SzFreePhysicsFS);
+        lzma_archive_exit(archive);
+        BAIL_MACRO(PHYSFS_ERR_OUT_OF_MEMORY, NULL);
+    }
+
+    /*
+     * Init with 0 so we know when a folder is already cached
+     * Values will be set by LZMA_read()
+     */
+    memset(archive->folders, 0, len);
+
+    if(!lzma_files_init(archive))
+    {
+        SzArDbExFree(&archive->db, SzFreePhysicsFS);
+        lzma_archive_exit(archive);
+        BAIL_MACRO(PHYSFS_ERR_OTHER_ERROR, NULL);
+    }
+
+    return archive;
+} /* LZMA_openArchive */
+
+
+/*
+ * Moved to seperate function so we can use alloca then immediately throw
+ *  away the allocated stack space...
+ */
+static void doEnumCallback(PHYSFS_EnumFilesCallback cb, void *callbackdata,
+                           const char *odir, const char *str, size_t flen)
+{
+    char *newstr = __PHYSFS_smallAlloc(flen + 1);
+    if (newstr == NULL)
+        return;
+
+    memcpy(newstr, str, flen);
+    newstr[flen] = '\0';
+    cb(callbackdata, odir, newstr);
+    __PHYSFS_smallFree(newstr);
+} /* doEnumCallback */
+
+
+static void LZMA_enumerateFiles(PHYSFS_Dir *opaque, const char *dname,
+                                int omitSymLinks, PHYSFS_EnumFilesCallback cb,
+                                const char *origdir, void *callbackdata)
+{
+    size_t dlen = strlen(dname),
+           dlen_inc = dlen + ((dlen > 0) ? 1 : 0);
+    LZMAarchive *archive = (LZMAarchive *) opaque;
+    LZMAfile *file = NULL,
+            *lastFile = &archive->files[archive->db.Database.NumFiles];
+        if (dlen)
+        {
+            file = lzma_find_file(archive, dname);
+            if (file != NULL) /* if 'file' is NULL it should stay so, otherwise errors will not be handled */
+                file += 1;
+        }
+        else
+        {
+            file = archive->files;
+        }
+
+    BAIL_IF_MACRO(file == NULL, PHYSFS_ERR_NO_SUCH_PATH, );
+
+    while (file < lastFile)
+    {
+        const char * fname = file->item->Name;
+        const char * dirNameEnd = fname + dlen_inc;
+
+        if (strncmp(dname, fname, dlen) != 0) /* Stop after mismatch, archive->files is sorted */
+            break;
+
+        if (strchr(dirNameEnd, '/')) /* Skip subdirs */
+        {
+            file++;
+            continue;
+        }
+
+        /* Do the actual callback... */
+        doEnumCallback(cb, callbackdata, origdir, dirNameEnd, strlen(dirNameEnd));
+
+        file++;
+    }
+} /* LZMA_enumerateFiles */
+
+
+static PHYSFS_Io *LZMA_openRead(PHYSFS_Dir *opaque, const char *name,
+                                int *fileExists)
+{
+    LZMAarchive *archive = (LZMAarchive *) opaque;
+    LZMAfile *file = lzma_find_file(archive, name);
+    PHYSFS_Io *io = NULL;
+
+    *fileExists = (file != NULL);
+    BAIL_IF_MACRO(file == NULL, PHYSFS_ERR_NO_SUCH_PATH, NULL);
+    BAIL_IF_MACRO(file->folder == NULL, PHYSFS_ERR_NOT_A_FILE, NULL);
+
+    file->position = 0;
+    file->folder->references++; /* Increase refcount for automatic cleanup... */
+
+    io = (PHYSFS_Io *) allocator.Malloc(sizeof (PHYSFS_Io));
+    BAIL_IF_MACRO(io == NULL, PHYSFS_ERR_OUT_OF_MEMORY, NULL);
+    memcpy(io, &LZMA_Io, sizeof (*io));
+    io->opaque = file;
+
+    return io;
+} /* LZMA_openRead */
+
+
+static PHYSFS_Io *LZMA_openWrite(PHYSFS_Dir *opaque, const char *filename)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, NULL);
+} /* LZMA_openWrite */
+
+
+static PHYSFS_Io *LZMA_openAppend(PHYSFS_Dir *opaque, const char *filename)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, NULL);
+} /* LZMA_openAppend */
+
+
+static void LZMA_closeArchive(PHYSFS_Dir *opaque)
+{
+    LZMAarchive *archive = (LZMAarchive *) opaque;
+
+#if 0  /* !!! FIXME: you shouldn't have to do this. */
+    PHYSFS_uint32 fileIndex = 0, numFiles = archive->db.Database.NumFiles;
+    for (fileIndex = 0; fileIndex < numFiles; fileIndex++)
+    {
+        LZMA_fileClose(&archive->files[fileIndex]);
+    } /* for */
+#endif
+
+    SzArDbExFree(&archive->db, SzFreePhysicsFS);
+    archive->stream.io->destroy(archive->stream.io);
+    lzma_archive_exit(archive);
+} /* LZMA_closeArchive */
+
+
+static int LZMA_remove(PHYSFS_Dir *opaque, const char *name)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, 0);
+} /* LZMA_remove */
+
+
+static int LZMA_mkdir(PHYSFS_Dir *opaque, const char *name)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, 0);
+} /* LZMA_mkdir */
+
+static int LZMA_stat(PHYSFS_Dir *opaque, const char *filename,
+                     int *exists, PHYSFS_Stat *stat)
+{
+    const LZMAarchive *archive = (const LZMAarchive *) opaque;
+    const LZMAfile *file = lzma_find_file(archive, filename);
+
+    *exists = (file != 0);
+    if (!file)
+        return 0;
+
+    if(file->item->IsDirectory)
+    {
+        stat->filesize = 0;
+        stat->filetype = PHYSFS_FILETYPE_DIRECTORY;
+    } /* if */
+    else
+    {
+        stat->filesize = (PHYSFS_sint64) file->item->Size;
+        stat->filetype = PHYSFS_FILETYPE_REGULAR;
+    } /* else */
+
+    /* !!! FIXME: the 0's should be -1's? */
+    if (file->item->IsLastWriteTimeDefined)
+        stat->modtime = lzma_filetime_to_unix_timestamp(&file->item->LastWriteTime);
+    else
+        stat->modtime = 0;
+
+    /* real create and accesstype are currently not in the lzma SDK */
+    stat->createtime = stat->modtime;
+    stat->accesstime = 0;
+
+    stat->readonly = 1;  /* 7zips are always read only */
+
+    return 1;
+} /* LZMA_stat */
+
+
+const PHYSFS_Archiver __PHYSFS_Archiver_LZMA =
+{
+    {
+        "7Z",
+        "LZMA (7zip) format",
+        "Dennis Schridde <devurandom@gmx.net>",
+        "http://icculus.org/physfs/",
+    },
+    LZMA_openArchive,        /* openArchive() method    */
+    LZMA_enumerateFiles,     /* enumerateFiles() method */
+    LZMA_openRead,           /* openRead() method       */
+    LZMA_openWrite,          /* openWrite() method      */
+    LZMA_openAppend,         /* openAppend() method     */
+    LZMA_remove,             /* remove() method         */
+    LZMA_mkdir,              /* mkdir() method          */
+    LZMA_closeArchive,       /* closeArchive() method   */
+    LZMA_stat                /* stat() method           */
+};
+
+#endif  /* defined PHYSFS_SUPPORTS_7Z */
+
+/* end of lzma.c ... */
+