changeset 8:dca15bb29d35

Initial add.
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 18 Sep 2001 10:54:21 +0000
parents 29313c20963d
children 2606137cf481
files extra_rwops.c extra_rwops.h
diffstat 2 files changed, 206 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/extra_rwops.c	Tue Sep 18 10:54:21 2001 +0000
@@ -0,0 +1,135 @@
+/*
+ * SDL_sound -- An abstract sound format decoding API.
+ * Copyright (C) 2001  Ryan C. Gordon.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * Some extra RWops that are needed or are just handy to have.
+ *
+ * Please see the file LICENSE in the source's root directory.
+ *
+ *  This file written by Ryan C. Gordon. (icculus@clutteredmind.org)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "SDL.h"
+
+
+    /*
+     * The Reference Counter RWops...
+     */
+
+
+typedef struct
+{
+    SDL_RWops *rw;  /* The actual RWops we're refcounting... */
+    int refcount;   /* The refcount; starts at 1. If goes to 0, delete. */
+} RWRefCounterData;
+
+
+/* Just pass through to the actual SDL_RWops's method... */
+static int refcounter_seek(SDL_RWops *rw, int offset, int whence)
+{
+    RWRefCounterData *data = (RWRefCounterData *) rw->hidden.unknown.data1;
+    return(data->rw->seek(data->rw, offset, whence));
+} /* refcounter_seek */
+
+
+/* Just pass through to the actual SDL_RWops's method... */
+static int refcounter_read(SDL_RWops *rw, void *ptr, int size, int maxnum)
+{
+    RWRefCounterData *data = (RWRefCounterData *) rw->hidden.unknown.data1;
+    return(data->rw->read(data->rw, ptr, size, maxnum));
+} /* refcounter_read */
+
+
+/* Just pass through to the actual SDL_RWops's method... */
+static int refcounter_write(SDL_RWops *rw, const void *ptr, int size, int num)
+{
+    RWRefCounterData *data = (RWRefCounterData *) rw->hidden.unknown.data1;
+    return(data->rw->write(data->rw, ptr, size, num));
+} /* refcounter_write */
+
+
+/*
+ * Decrement the reference count. If there are no more references, pass
+ *   through to the actual SDL_RWops's method, and then clean ourselves up.
+ */
+static int refcounter_close(SDL_RWops *rw)
+{
+    int retval = 0;
+    RWRefCounterData *data = (RWRefCounterData *) rw->hidden.unknown.data1;
+    data->refcount--;
+    if (data->refcount <= 0)
+    {
+        retval = data->rw->close(data->rw);
+        free(data);
+        SDL_FreeRW(rw);
+    } /* if */
+
+    return(retval);
+} /* refcounter_close */
+
+
+void RWops_RWRefCounter_addRef(SDL_RWops *rw)
+{
+    RWRefCounterData *data = (RWRefCounterData *) rw->hidden.unknown.data1;
+    data->refcount++;
+} /* RWops_RWRefCounter_addRef */
+
+
+SDL_RWops *RWops_RWRefCounter_new(SDL_RWops *rw)
+{
+    SDL_RWops *retval = NULL;
+
+    if (rw == NULL)
+    {
+        SDL_SetError("NULL argument to RWops_RWRefCounter_new().");
+        return(NULL);
+    } /* if */
+
+    retval = SDL_AllocRW();
+    if (retval != NULL)
+    {
+        RWRefCounterData *data;
+        data = (RWRefCounterData *) malloc(sizeof (RWRefCounterData));
+        if (data == NULL)
+        {
+            SDL_OutOfMemory();
+            SDL_FreeRW(retval);
+            retval = NULL;
+        } /* if */
+        else
+        {
+            data->rw = rw;
+            data->refcount = 1;
+            retval->hidden.unknown.data1 = data;
+            retval->seek = refcounter_seek;
+            retval->read = refcounter_read;
+            retval->write = refcounter_write;
+            retval->close = refcounter_close;
+        } /* else */
+    } /* if */
+
+    return(retval);
+} /* RWops_RWRefCounter_new */
+
+
+/* end of extra_rwops.c ... */
+
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/extra_rwops.h	Tue Sep 18 10:54:21 2001 +0000
@@ -0,0 +1,71 @@
+/*
+ * SDL_sound -- An abstract sound format decoding API.
+ * Copyright (C) 2001  Ryan C. Gordon.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * Some extra RWops that are needed or are just handy to have.
+ *
+ * Please see the file LICENSE in the source's root directory.
+ *
+ *  This file written by Ryan C. Gordon. (icculus@clutteredmind.org)
+ */
+
+#ifndef _INCLUDE_EXTRA_RWOPS_H_
+#define _INCLUDE_EXTRA_RWOPS_H_
+
+#include "SDL.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * The Reference Counter RWops...
+ *
+ *  This wraps another RWops with a reference counter. When you create a
+ *   reference counter RWops, it sets a counter to one. Everytime you call
+ *   RWops_RWRefCounter_new(), that's RWops's counter increments by one.
+ *   Everytime you call that RWops's close() method, the counter decrements
+ *   by one. If the counter hits zero, the original RWops's close() method
+ *   is called, and the reference counting wrapper deletes itself. The read,
+ *   write, and seek methods just pass through to the original.
+ *
+ *  This is handy if you have two libraries (in the original case, SDL_sound
+ *   and SMPEG), who both want an SDL_RWops, and both want to close it when
+ *   they are finished. This resolves that contention. The user creates a
+ *   RWops, passes it to SDL_sound, which wraps it in a reference counter and
+ *   increments the number of references, and passes the wrapped RWops to
+ *   SMPEG. SMPEG "closes" this wrapped RWops when the MP3 has finished
+ *   playing, and SDL_sound then closes it, too. This second closing removes
+ *   the last reference, and the RWops is smoothly destructed.
+ */
+
+/* Return a SDL_RWops that is a reference counting wrapper of (rw). */
+SDL_RWops *RWops_RWRefCounter_new(SDL_RWops *rw);
+
+/* Increment a reference counting RWops's refcount by one. */
+void RWops_RWRefCounter_addRef(SDL_RWops *rw);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* !defined _INCLUDE_EXTRA_RWOPS_H_ */
+
+/* end of extra_rwops.h ... */
+