diff options
Diffstat (limited to 'src/core/lib/transport/chttp2/hpack_table.h')
| -rw-r--r-- | src/core/lib/transport/chttp2/hpack_table.h | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/src/core/lib/transport/chttp2/hpack_table.h b/src/core/lib/transport/chttp2/hpack_table.h new file mode 100644 index 0000000000..2cbc02dd9c --- /dev/null +++ b/src/core/lib/transport/chttp2/hpack_table.h @@ -0,0 +1,108 @@ +/* + * + * Copyright 2015-2016, 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_CORE_LIB_TRANSPORT_CHTTP2_HPACK_TABLE_H +#define GRPC_CORE_LIB_TRANSPORT_CHTTP2_HPACK_TABLE_H + +#include <grpc/support/port_platform.h> +#include <grpc/support/slice.h> +#include "src/core/lib/transport/metadata.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 +#if 0 +/* 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) +#endif + +/* hpack decoder table */ +typedef struct { + /* the first used entry in ents */ + uint32_t first_ent; + /* how many entries are in the table */ + uint32_t num_ents; + /* the amount of memory used by the table, according to the hpack algorithm */ + uint32_t mem_used; + /* the max memory allowed to be used by the table, according to the hpack + algorithm */ + uint32_t max_bytes; + /* the currently agreed size of the table, according to the hpack algorithm */ + uint32_t current_table_bytes; + /* Maximum number of entries we could possibly fit in the table, given defined + overheads */ + uint32_t max_entries; + /* Number of entries allocated in ents */ + uint32_t cap_entries; + /* 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_mdelem *static_ents[GRPC_CHTTP2_LAST_STATIC_ENTRY]; +} grpc_chttp2_hptbl; + +/* initialize a hpack table */ +void grpc_chttp2_hptbl_init(grpc_chttp2_hptbl *tbl); +void grpc_chttp2_hptbl_destroy(grpc_chttp2_hptbl *tbl); +void grpc_chttp2_hptbl_set_max_bytes(grpc_chttp2_hptbl *tbl, + uint32_t max_bytes); +int grpc_chttp2_hptbl_set_current_table_size(grpc_chttp2_hptbl *tbl, + uint32_t bytes); + +/* lookup a table entry based on its hpack index */ +grpc_mdelem *grpc_chttp2_hptbl_lookup(const grpc_chttp2_hptbl *tbl, + uint32_t index); +/* add a table entry to the index */ +int grpc_chttp2_hptbl_add(grpc_chttp2_hptbl *tbl, + grpc_mdelem *md) GRPC_MUST_USE_RESULT; +/* 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 { + uint32_t index; + int 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_CORE_LIB_TRANSPORT_CHTTP2_HPACK_TABLE_H */ |