Initial interfaces for file i/o.

icculus · Mar 23, 2006 · 55019d8 · 55019d8
1 parent 831f51c
commit 55019d8
Showing 1 changed file with 65 additions and 0 deletions.
diff --git a/fileio.h b/fileio.h
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+#ifndef _INCL_FILEIO_H_
+#define _INCL_FILEIO_H_
+
+#include "universal.h"
+
+/*
+ * File i/o may go through multiple layers: the archive attached to the binary,
+ *  then an archive in there that's being read entirely out of memory that's
+ *  being uncompressed to on the fly, or it might be a straight read from a
+ *  regular uncompressed file on physical media. It might be a single file
+ *  compressed with bzip2. As such, we have to have an abstraction over the
+ *  usual channels...basically what we need here is archives-within-archives,
+ *  done transparently and with arbitrary depth (although usually not more
+ *  than one deep. This also works as a general transport layer, so the
+ *  abstraction could be extended to network connections and such, too.
+ */
+
+/* Abstract input interface. Files, memory, archive entries, etc. */
+typedef struct MojoInput MojoInput;
+struct MojoInput
+{
+    /*public*/
+    size_t (*read)(MojoInput *io, void *buf, size_t bufsize);
+    boolean (*seek)(MojoInput *io, uint64 pos);
+    uint64 (*tell)(MojoInput *io);
+    void (*close)(MojoInput *io);
+
+    /*private*/
+    void *opaque;
+};
+
+MojoInput *MojoInput_newFromFile(const char *fname);
+MojoInput *MojoInput_newFromMemory(void *mem, size_t bytes);
+
+
+/* Abstract archive interface. Archives, directories, etc. */
+typedef struct MojoArchiveEntryInfo MojoArchiveEntryInfo;
+struct MojoArchiveEntryInfo
+{
+    const char *filename;
+    MojoArchiveEntryType type;
+    sint64 filesize;
+};
+
+typedef struct MojoArchive MojoArchive;
+struct MojoArchive 
+{
+    /*public*/
+    void (*restartEnumeration)(MojoArchive *ar);
+    const MojoArchiveEntryInfo* (*enumEntry)(MojoArchive *ar);
+    MojoInput* (*openCurrentEntry)(MojoArchive *ar);
+    void (*close)(MojoArchive *ar);
+
+    /*private*/
+    MojoInput *io;
+    MojoArchiveEntryInfo lastEnumInfo;
+    void *opaque;
+};
+
+MojoArchive *MojoArchive_newFromInput(MojoInput *io, const char *origfname);
+
+#endif
+
+/* end of fileio.h ... */
+