mapi: Add a generic C dispatcher.

The idea is to have an API generate a header using mapi_abi.py.  The API
can then use the header to build a dispatcher.

1 files changed, 191 insertions, 0 deletions

diff --git a/src/mapi/mapi/mapi.c b/src/mapi/mapi/mapi.c
new file mode 100644
index 0000000000..2f1c3fff6c
--- /dev/null
+++ b/src/mapi/mapi/mapi.c
@@ -0,0 +1,191 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  7.9
+ *
+ * Copyright (C) 2010 LunarG Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Chia-I Wu <olv@lunarg.com>
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "u_current.h"
+#include "u_thread.h"
+#include "mapi.h"
+#include "stub.h"
+#include "table.h"
+
+/* dynamic stubs will run out before this array */
+#define MAPI_MAX_STUBS (sizeof(struct mapi_table) / sizeof(mapi_func))
+static const struct mapi_stub *mapi_stub_map[MAPI_MAX_STUBS];
+static int mapi_num_stubs;
+
+static const struct mapi_stub *
+get_stub(const char *name, const struct mapi_stub *alias)
+{
+   const struct mapi_stub *stub;
+
+   stub = stub_find_public(name);
+   if (!stub) {
+      struct mapi_stub *dyn = stub_find_dynamic(name, 1);
+      if (dyn) {
+         stub_fix_dynamic(dyn, alias);
+         stub = dyn;
+      }
+   }
+
+   return stub;
+}
+
+/**
+ * Initialize mapi.  spec consists of NULL-separated strings.  The first string
+ * denotes the version.  It is followed by variable numbers of entries.  Each
+ * entry can have multiple names.  An empty name terminates an entry.  An empty
+ * entry terminates the spec.  A spec of two entries, Foo and Bar, is as
+ * follows
+ *
+ *   "1\0"
+ *   "Foo\0"
+ *   "FooEXT\0"
+ *   "\0"
+ *   "Bar\0"
+ *   "\0"
+ */
+void
+mapi_init(const char *spec)
+{
+   u_mutex_declare_static(mutex);
+   const char *p;
+   int ver, count;
+
+   u_mutex_lock(mutex);
+
+   /* already initialized */
+   if (mapi_num_stubs) {
+      u_mutex_unlock(mutex);
+      return;
+   }
+
+   count = 0;
+   p = spec;
+
+   /* parse version string */
+   ver = atoi(p);
+   if (ver != 1) {
+      u_mutex_unlock(mutex);
+      return;
+   }
+   p += strlen(p) + 1;
+
+   while (*p) {
+      const struct mapi_stub *stub;
+
+      stub = get_stub(p, NULL);
+      /* out of dynamic entries */
+      if (!stub)
+         break;
+      p += strlen(p) + 1;
+
+      while (*p) {
+         get_stub(p, stub);
+         p += strlen(p) + 1;
+      }
+
+      mapi_stub_map[count++] = stub;
+      p++;
+   }
+
+   mapi_num_stubs = count;
+
+   u_mutex_unlock(mutex);
+}
+
+/**
+ * Return the address of an entry.  Optionally generate the entry if it does
+ * not exist.
+ */
+mapi_proc
+mapi_get_proc_address(const char *name)
+{
+   const struct mapi_stub *stub;
+
+   stub = stub_find_public(name);
+   if (!stub)
+      stub = stub_find_dynamic(name, 0);
+
+   return (stub) ? (mapi_proc) stub->addr : NULL;
+}
+
+/**
+ * Create a dispatch table.
+ */
+struct mapi_table *
+mapi_table_create(void)
+{
+   const struct mapi_table *noop = table_get_noop();
+   struct mapi_table *tbl;
+
+   tbl = malloc(sizeof(*tbl));
+   if (tbl)
+      memcpy(tbl, noop, sizeof(*tbl));
+
+   return tbl;
+}
+
+/**
+ * Destroy a dispatch table.
+ */
+void
+mapi_table_destroy(struct mapi_table *tbl)
+{
+   free(tbl);
+}
+
+/**
+ * Fill a dispatch table.  The order of the procs is determined when mapi_init
+ * is called.
+ */
+void
+mapi_table_fill(struct mapi_table *tbl, const mapi_proc *procs)
+{
+   const struct mapi_table *noop = table_get_noop();
+   int i;
+
+   for (i = 0; i < mapi_num_stubs; i++) {
+      const struct mapi_stub *stub = mapi_stub_map[i];
+      mapi_func func = (mapi_func) procs[i];
+
+      if (!func)
+         func = table_get_func(noop, stub);
+      table_set_func(tbl, stub, func);
+   }
+}
+
+/**
+ * Make a dispatch table current.
+ */
+void
+mapi_table_make_current(const struct mapi_table *tbl)
+{
+   u_current_set(tbl);
+}