Initial checkin of gRPC to third_party/

third_party/grpc/src/core/transport/chttp2/stream_map.c

Index: third_party/grpc/src/core/transport/chttp2/stream_map.c
diff --git a/third_party/grpc/src/core/transport/chttp2/stream_map.c b/third_party/grpc/src/core/transport/chttp2/stream_map.c
new file mode 100644
index 0000000000000000000000000000000000000000..555a16fb72bd7bd477d41c3ab7bdfd9a84edce56
--- /dev/null
+++ b/third_party/grpc/src/core/transport/chttp2/stream_map.c
@@ -0,0 +1,197 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/transport/chttp2/stream_map.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/useful.h>
+
+void grpc_chttp2_stream_map_init(grpc_chttp2_stream_map *map,
+                                 size_t initial_capacity) {
+  GPR_ASSERT(initial_capacity > 1);
+  map->keys = gpr_malloc(sizeof(uint32_t) * initial_capacity);
+  map->values = gpr_malloc(sizeof(void *) * initial_capacity);
+  map->count = 0;
+  map->free = 0;
+  map->capacity = initial_capacity;
+}
+
+void grpc_chttp2_stream_map_destroy(grpc_chttp2_stream_map *map) {
+  gpr_free(map->keys);
+  gpr_free(map->values);
+}
+
+static size_t compact(uint32_t *keys, void **values, size_t count) {
+  size_t i, out;
+
+  for (i = 0, out = 0; i < count; i++) {
+    if (values[i]) {
+      keys[out] = keys[i];
+      values[out] = values[i];
+      out++;
+    }
+  }
+
+  return out;
+}
+
+void grpc_chttp2_stream_map_add(grpc_chttp2_stream_map *map, uint32_t key,
+                                void *value) {
+  size_t count = map->count;
+  size_t capacity = map->capacity;
+  uint32_t *keys = map->keys;
+  void **values = map->values;
+
+  GPR_ASSERT(count == 0 || keys[count - 1] < key);
+  GPR_ASSERT(value);
+
+  if (count == capacity) {
+    if (map->free > capacity / 4) {
+      count = compact(keys, values, count);
+      map->free = 0;
+    } else {
+      /* resize when less than 25% of the table is free, because compaction
+         won't help much */
+      map->capacity = capacity = 3 * capacity / 2;
+      map->keys = keys = gpr_realloc(keys, capacity * sizeof(uint32_t));
+      map->values = values = gpr_realloc(values, capacity * sizeof(void *));
+    }
+  }
+
+  keys[count] = key;
+  values[count] = value;
+  map->count = count + 1;
+}
+
+void grpc_chttp2_stream_map_move_into(grpc_chttp2_stream_map *src,
+                                      grpc_chttp2_stream_map *dst) {
+  /* if src is empty we dont need to do anything */
+  if (src->count == src->free) {
+    return;
+  }
+  /* if dst is empty we simply need to swap */
+  if (dst->count == dst->free) {
+    GPR_SWAP(grpc_chttp2_stream_map, *src, *dst);
+    return;
+  }
+  /* the first element of src must be greater than the last of dst...
+   * however the maps may need compacting for this property to hold */
+  if (src->keys[0] <= dst->keys[dst->count - 1]) {
+    src->count = compact(src->keys, src->values, src->count);
+    src->free = 0;
+    dst->count = compact(dst->keys, dst->values, dst->count);
+    dst->free = 0;
+  }
+  GPR_ASSERT(src->keys[0] > dst->keys[dst->count - 1]);
+  /* if dst doesn't have capacity, resize */
+  if (dst->count + src->count > dst->capacity) {
+    dst->capacity = GPR_MAX(dst->capacity * 3 / 2, dst->count + src->count);
+    dst->keys = gpr_realloc(dst->keys, dst->capacity * sizeof(uint32_t));
+    dst->values = gpr_realloc(dst->values, dst->capacity * sizeof(void *));
+  }
+  memcpy(dst->keys + dst->count, src->keys, src->count * sizeof(uint32_t));
+  memcpy(dst->values + dst->count, src->values, src->count * sizeof(void *));
+  dst->count += src->count;
+  dst->free += src->free;
+  src->count = 0;
+  src->free = 0;
+}
+
+static void **find(grpc_chttp2_stream_map *map, uint32_t key) {
+  size_t min_idx = 0;
+  size_t max_idx = map->count;
+  size_t mid_idx;
+  uint32_t *keys = map->keys;
+  void **values = map->values;
+  uint32_t mid_key;
+
+  if (max_idx == 0) return NULL;
+
+  while (min_idx < max_idx) {
+    /* find the midpoint, avoiding overflow */
+    mid_idx = min_idx + ((max_idx - min_idx) / 2);
+    mid_key = keys[mid_idx];
+
+    if (mid_key < key) {
+      min_idx = mid_idx + 1;
+    } else if (mid_key > key) {
+      max_idx = mid_idx;
+    } else /* mid_key == key */
+    {
+      return &values[mid_idx];
+    }
+  }
+
+  return NULL;
+}
+
+void *grpc_chttp2_stream_map_delete(grpc_chttp2_stream_map *map, uint32_t key) {
+  void **pvalue = find(map, key);
+  void *out = NULL;
+  if (pvalue != NULL) {
+    out = *pvalue;
+    *pvalue = NULL;
+    map->free += (out != NULL);
+    /* recognize complete emptyness and ensure we can skip
+     * defragmentation later */
+    if (map->free == map->count) {
+      map->free = map->count = 0;
+    }
+  }
+  return out;
+}
+
+void *grpc_chttp2_stream_map_find(grpc_chttp2_stream_map *map, uint32_t key) {
+  void **pvalue = find(map, key);
+  return pvalue != NULL ? *pvalue : NULL;
+}
+
+size_t grpc_chttp2_stream_map_size(grpc_chttp2_stream_map *map) {
+  return map->count - map->free;
+}
+
+void grpc_chttp2_stream_map_for_each(grpc_chttp2_stream_map *map,
+                                     void (*f)(void *user_data, uint32_t key,
+                                               void *value),
+                                     void *user_data) {
+  size_t i;
+
+  for (i = 0; i < map->count; i++) {
+    if (map->values[i]) {
+      f(user_data, map->keys[i], map->values[i]);
+    }
+  }
+}