pipeline-cache: Use a shared hash table wrapper

The pipeline cache contains three separate hash tables, one for the
state affecting the vertex shaders, one for the fragment shaders and
one for the resulting combined program. Previously these hash tables
had a fair bit of duplicated code to calculate the hashes, check for
equality and copy the pipeline when it is added. This patch moves the
common bits of code to a new type called CoglPipelineHashTable which
just wraps a GHashTable with a given set of state flags to use for
hashing and checking for equality.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 402796430c839038339e531363b8c2463f9b2a9e)

Conflicts:
	cogl/Makefile.am

1 files changed, 69 insertions, 0 deletions

diff --git a/cogl/cogl-pipeline-hash-table.h b/cogl/cogl-pipeline-hash-table.h
new file mode 100644
index 00000000..1b0a0d93
--- /dev/null
+++ b/cogl/cogl-pipeline-hash-table.h
@@ -0,0 +1,69 @@
+/*
+ * Cogl
+ *
+ * An object oriented GL/GLES Abstraction/Utility Layer
+ *
+ * Copyright (C) 2013 Intel Corporation.
+ *
+ * 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 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, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ */
+
+#ifndef __COGL_PIPELINE_HASH_H__
+#define __COGL_PIPELINE_HASH_H__
+
+#include "cogl-pipeline.h"
+
+typedef struct
+{
+  /* Total number of pipelines that were ever added to the hash. This
+   * is not decremented when a pipeline is removed. It is only used to
+   * generate a warning if an unusually high number of pipelines are
+   * generated */
+  int n_unique_pipelines;
+
+  /* String that will be used to describe the usage of this hash table
+   * in the debug warning when too many pipelines are generated. This
+   * must be a static string because it won't be copied or freed */
+  const char *debug_string;
+
+  unsigned int main_state;
+  unsigned int layer_state;
+
+  GHashTable *table;
+} CoglPipelineHashTable;
+
+void
+_cogl_pipeline_hash_table_init (CoglPipelineHashTable *hash,
+                                unsigned int main_state,
+                                unsigned int layer_state,
+                                const char *debug_string);
+
+void
+_cogl_pipeline_hash_table_destroy (CoglPipelineHashTable *hash);
+
+/*
+ * Gets a pipeline from the hash that has the same state as
+ * @key_pipeline according to the limited state bits passed to
+ * _cogl_pipeline_hash_table_init(). If there is no matching pipelines
+ * already then a copy of key_pipeline is stored in the hash so that
+ * it will be used next time the function is called with a similar
+ * pipeline. In that case the copy itself will be returned
+ */
+CoglPipeline *
+_cogl_pipeline_hash_table_get (CoglPipelineHashTable *hash,
+                               CoglPipeline *key_pipeline);
+
+#endif /* __COGL_PIPELINE_HASH_H__ */