Initial import.

1 files changed, 97 insertions, 0 deletions

diff --git a/src/core/transport/chttp2/hpack_table.h b/src/core/transport/chttp2/hpack_table.h
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+++ b/src/core/transport/chttp2/hpack_table.h
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+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef __GRPC_INTERNAL_TRANSPORT_CHTTP2_HPACK_TABLE_H__
+#define __GRPC_INTERNAL_TRANSPORT_CHTTP2_HPACK_TABLE_H__
+
+#include "src/core/transport/metadata.h"
+#include <grpc/support/port_platform.h>
+#include <grpc/support/slice.h>
+
+/* HPACK header table */
+
+/* last index in the static table */
+#define GRPC_CHTTP2_LAST_STATIC_ENTRY 61
+
+/* Initial table size as per the spec */
+#define GRPC_CHTTP2_INITIAL_HPACK_TABLE_SIZE 4096
+/* Maximum table size that we'll use */
+#define GRPC_CHTTP2_MAX_HPACK_TABLE_SIZE GRPC_CHTTP2_INITIAL_HPACK_TABLE_SIZE
+/* Per entry overhead bytes as per the spec */
+#define GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD 32
+/* Maximum number of entries we could possibly fit in the table, given defined
+   overheads */
+#define GRPC_CHTTP2_MAX_TABLE_COUNT                                            \
+  ((GRPC_CHTTP2_MAX_HPACK_TABLE_SIZE + GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD - 1) / \
+   GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD)
+
+/* hpack decoder table */
+typedef struct {
+  grpc_mdctx *mdctx;
+  /* the first used entry in ents */
+  gpr_uint16 first_ent;
+  /* the last used entry in ents */
+  gpr_uint16 last_ent;
+  /* how many entries are in the table */
+  gpr_uint16 num_ents;
+  /* the amount of memory used by the table, according to the hpack algorithm */
+  gpr_uint16 mem_used;
+  /* the max memory allowed to be used by the table, according to the hpack
+     algorithm */
+  gpr_uint16 max_bytes;
+  /* a circular buffer of headers - this is stored in the opposite order to
+     what hpack specifies, in order to simplify table management a little...
+     meaning lookups need to SUBTRACT from the end position */
+  grpc_mdelem *ents[GRPC_CHTTP2_MAX_TABLE_COUNT];
+  grpc_mdelem *static_ents[GRPC_CHTTP2_LAST_STATIC_ENTRY];
+} grpc_chttp2_hptbl;
+
+/* initialize a hpack table */
+void grpc_chttp2_hptbl_init(grpc_chttp2_hptbl *tbl, grpc_mdctx *mdctx);
+void grpc_chttp2_hptbl_destroy(grpc_chttp2_hptbl *tbl);
+
+/* lookup a table entry based on its hpack index */
+grpc_mdelem *grpc_chttp2_hptbl_lookup(const grpc_chttp2_hptbl *tbl,
+                                      gpr_uint32 index);
+/* add a table entry to the index */
+void grpc_chttp2_hptbl_add(grpc_chttp2_hptbl *tbl, grpc_mdelem *md);
+/* Find a key/value pair in the table... returns the index in the table of the
+   most similar entry, or 0 if the value was not found */
+typedef struct {
+  gpr_uint16 index;
+  gpr_uint8 has_value;
+} grpc_chttp2_hptbl_find_result;
+grpc_chttp2_hptbl_find_result grpc_chttp2_hptbl_find(
+    const grpc_chttp2_hptbl *tbl, grpc_mdelem *md);
+
+#endif  /* __GRPC_INTERNAL_TRANSPORT_CHTTP2_HPACK_TABLE_H__ */