1 files changed, 155 insertions, 0 deletions
diff --git a/src/core/support/slice_buffer.c b/src/core/support/slice_buffer.c
new file mode 100644
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+++ b/src/core/support/slice_buffer.c
@@ -0,0 +1,155 @@
+/*
+ *
+ * Copyright 2014, 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 <grpc/support/slice_buffer.h>
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+/* initial allocation size (# of slices) */
+#define INITIAL_CAPACITY 4
+/* grow a buffer; requires INITIAL_CAPACITY > 1 */
+#define GROW(x) (3 * (x) / 2)
+
+void gpr_slice_buffer_init(gpr_slice_buffer *sb) {
+  sb->count = 0;
+  sb->length = 0;
+  sb->capacity = INITIAL_CAPACITY;
+  sb->slices = gpr_malloc(sizeof(gpr_slice) * INITIAL_CAPACITY);
+}
+
+void gpr_slice_buffer_destroy(gpr_slice_buffer *sb) {
+  gpr_slice_buffer_reset_and_unref(sb);
+  gpr_free(sb->slices);
+}
+
+gpr_uint8 *gpr_slice_buffer_tiny_add(gpr_slice_buffer *sb, int n) {
+  gpr_slice *back;
+  gpr_uint8 *out;
+
+  sb->length += n;
+
+  if (sb->count == 0) goto add_new;
+  back = &sb->slices[sb->count - 1];
+  if (back->refcount) goto add_new;
+  if (back->data.inlined.length + n > sizeof(back->data.inlined.bytes))
+    goto add_new;
+  out = back->data.inlined.bytes + back->data.inlined.length;
+  back->data.inlined.length += n;
+  return out;
+
+add_new:
+  if (sb->count == sb->capacity) {
+    sb->capacity = GROW(sb->capacity);
+    GPR_ASSERT(sb->capacity > sb->count);
+    sb->slices = gpr_realloc(sb->slices, sb->capacity * sizeof(gpr_slice));
+  }
+  back = &sb->slices[sb->count];
+  sb->count++;
+  back->refcount = NULL;
+  back->data.inlined.length = n;
+  return back->data.inlined.bytes;
+}
+
+size_t gpr_slice_buffer_add_indexed(gpr_slice_buffer *sb, gpr_slice s) {
+  size_t out = sb->count;
+  if (out == sb->capacity) {
+    sb->capacity = GROW(sb->capacity);
+    GPR_ASSERT(sb->capacity > sb->count);
+    sb->slices = gpr_realloc(sb->slices, sb->capacity * sizeof(gpr_slice));
+  }
+  sb->slices[out] = s;
+  sb->length += GPR_SLICE_LENGTH(s);
+  sb->count = out + 1;
+  return out;
+}
+
+void gpr_slice_buffer_add(gpr_slice_buffer *sb, gpr_slice s) {
+  size_t n = sb->count;
+  /* if both the last slice in the slice buffer and the slice being added
+     are inlined (that is, that they carry their data inside the slice data
+     structure), and the back slice is not full, then concatenate directly
+     into the back slice, preventing many small slices being passed into
+     writes */
+  if (!s.refcount && n) {
+    gpr_slice *back = &sb->slices[n - 1];
+    if (!back->refcount && back->data.inlined.length < GPR_SLICE_INLINED_SIZE) {
+      if (s.data.inlined.length + back->data.inlined.length <=
+          GPR_SLICE_INLINED_SIZE) {
+        memcpy(back->data.inlined.bytes + back->data.inlined.length,
+               s.data.inlined.bytes, s.data.inlined.length);
+        back->data.inlined.length += s.data.inlined.length;
+      } else {
+        size_t cp1 = GPR_SLICE_INLINED_SIZE - back->data.inlined.length;
+        memcpy(back->data.inlined.bytes + back->data.inlined.length,
+               s.data.inlined.bytes, cp1);
+        back->data.inlined.length = GPR_SLICE_INLINED_SIZE;
+        if (n == sb->capacity) {
+          sb->capacity = GROW(sb->capacity);
+          GPR_ASSERT(sb->capacity > sb->count);
+          sb->slices =
+              gpr_realloc(sb->slices, sb->capacity * sizeof(gpr_slice));
+        }
+        back = &sb->slices[n];
+        sb->count = n + 1;
+        back->refcount = NULL;
+        back->data.inlined.length = s.data.inlined.length - cp1;
+        memcpy(back->data.inlined.bytes, s.data.inlined.bytes + cp1,
+               s.data.inlined.length - cp1);
+      }
+      sb->length += s.data.inlined.length;
+      return; /* early out */
+    }
+  }
+  gpr_slice_buffer_add_indexed(sb, s);
+}
+
+void gpr_slice_buffer_addn(gpr_slice_buffer *sb, gpr_slice *s, size_t n) {
+  size_t i;
+  for (i = 0; i < n; i++) {
+    gpr_slice_buffer_add(sb, s[i]);
+  }
+}
+
+void gpr_slice_buffer_reset_and_unref(gpr_slice_buffer *sb) {
+  size_t i;
+
+  for (i = 0; i < sb->count; i++) {
+    gpr_slice_unref(sb->slices[i]);
+  }
+
+  sb->count = 0;
+  sb->length = 0;
+}