| /* |
| * |
| * 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. |
| * |
| */ |
| |
| #ifndef GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_TABLE_H |
| #define GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_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_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_TABLE_H */ |