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author | Nicolas Noble <nicolasnoble@users.noreply.github.com> | 2015-06-24 12:59:30 -0700 |
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committer | Nicolas Noble <nicolasnoble@users.noreply.github.com> | 2015-06-24 12:59:30 -0700 |
commit | 1e02fed4a1e77f603a4356c349802c8dcae7886f (patch) | |
tree | 1877330155cc5b4648a2e5f07b802ed1acad1995 /src/core | |
parent | 5fbec19749a2bd00013d64c84aec36e721d9d010 (diff) | |
parent | 31489e3abaab3bd0d4238d35e2d68477316eb6d9 (diff) |
Merge pull request #2185 from ctiller/it-hides-them
Move some code out of src/ into tools/
Diffstat (limited to 'src/core')
-rw-r--r-- | src/core/transport/chttp2/gen_hpack_tables.c | 362 |
1 files changed, 0 insertions, 362 deletions
diff --git a/src/core/transport/chttp2/gen_hpack_tables.c b/src/core/transport/chttp2/gen_hpack_tables.c deleted file mode 100644 index bdaa3cf094..0000000000 --- a/src/core/transport/chttp2/gen_hpack_tables.c +++ /dev/null @@ -1,362 +0,0 @@ -/* - * - * 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. - * - */ - -/* generates constant tables for hpack.c */ - -#include <stddef.h> -#include <stdio.h> -#include <string.h> -#include <assert.h> - -#include <grpc/support/log.h> -#include "src/core/transport/chttp2/huffsyms.h" - -/* - * first byte LUT generation - */ - -typedef struct { - const char *call; - /* bit prefix for the field type */ - unsigned char prefix; - /* length of the bit prefix for the field type */ - unsigned char prefix_length; - /* index value: 0 = all zeros, 2 = all ones, 1 otherwise */ - unsigned char index; -} spec; - -static const spec fields[] = {{"INDEXED_FIELD", 0X80, 1, 1}, - {"INDEXED_FIELD_X", 0X80, 1, 2}, - {"LITHDR_INCIDX", 0X40, 2, 1}, - {"LITHDR_INCIDX_X", 0X40, 2, 2}, - {"LITHDR_INCIDX_V", 0X40, 2, 0}, - {"LITHDR_NOTIDX", 0X00, 4, 1}, - {"LITHDR_NOTIDX_X", 0X00, 4, 2}, - {"LITHDR_NOTIDX_V", 0X00, 4, 0}, - {"LITHDR_NVRIDX", 0X10, 4, 1}, - {"LITHDR_NVRIDX_X", 0X10, 4, 2}, - {"LITHDR_NVRIDX_V", 0X10, 4, 0}, - {"MAX_TBL_SIZE", 0X20, 3, 1}, - {"MAX_TBL_SIZE_X", 0X20, 3, 2}, }; - -static const int num_fields = sizeof(fields) / sizeof(*fields); - -static unsigned char prefix_mask(unsigned char prefix_len) { - unsigned char i; - unsigned char out = 0; - for (i = 0; i < prefix_len; i++) { - out |= 1 << (7 - i); - } - return out; -} - -static unsigned char suffix_mask(unsigned char prefix_len) { - return ~prefix_mask(prefix_len); -} - -static void generate_first_byte_lut(void) { - int i, j, n; - const spec *chrspec; - unsigned char suffix; - - n = printf("static CALLTYPE first_byte[256] = {"); - /* for each potential first byte of a header */ - for (i = 0; i < 256; i++) { - /* find the field type that matches it */ - chrspec = NULL; - for (j = 0; j < num_fields; j++) { - if ((prefix_mask(fields[j].prefix_length) & i) == fields[j].prefix) { - suffix = suffix_mask(fields[j].prefix_length) & i; - if (suffix == suffix_mask(fields[j].prefix_length)) { - if (fields[j].index != 2) continue; - } else if (suffix == 0) { - if (fields[j].index != 0) continue; - } else { - if (fields[j].index != 1) continue; - } - GPR_ASSERT(chrspec == NULL); - chrspec = &fields[j]; - } - } - if (chrspec) { - n += printf("%s, ", chrspec->call); - } else { - n += printf("ILLEGAL, "); - } - /* make some small effort towards readable output */ - if (n > 70) { - printf("\n "); - n = 2; - } - } - printf("};\n"); -} - -/* - * Huffman decoder table generation - */ - -#define MAXHUFFSTATES 1024 - -/* represents a set of symbols as an array of booleans indicating inclusion */ -typedef struct { - char included[GRPC_CHTTP2_NUM_HUFFSYMS]; -} symset; -/* represents a lookup table indexed by a nibble */ -typedef struct { - int values[16]; -} nibblelut; - -/* returns a symset that includes all possible symbols */ -static symset symset_all(void) { - symset x; - memset(x.included, 1, sizeof(x.included)); - return x; -} - -/* returns a symset that includes no symbols */ -static symset symset_none(void) { - symset x; - memset(x.included, 0, sizeof(x.included)); - return x; -} - -/* returns an empty nibblelut */ -static nibblelut nibblelut_empty(void) { - nibblelut x; - int i; - for (i = 0; i < 16; i++) { - x.values[i] = -1; - } - return x; -} - -/* counts symbols in a symset - only used for debug builds */ -#ifndef NDEBUG -static int nsyms(symset s) { - int i; - int c = 0; - for (i = 0; i < GRPC_CHTTP2_NUM_HUFFSYMS; i++) { - c += s.included[i] != 0; - } - return c; -} -#endif - -/* global table of discovered huffman decoding states */ -static struct { - /* the bit offset that this state starts at */ - int bitofs; - /* the set of symbols that this state started with */ - symset syms; - - /* lookup table for the next state */ - nibblelut next; - /* lookup table for what to emit */ - nibblelut emit; -} huffstates[MAXHUFFSTATES]; -static int nhuffstates = 0; - -/* given a number of decoded bits and a set of symbols that are live, - return the index into the decoder table for this state. - set isnew to 1 if this state was previously undiscovered */ -static int state_index(int bitofs, symset syms, int *isnew) { - int i; - for (i = 0; i < nhuffstates; i++) { - if (huffstates[i].bitofs != bitofs) continue; - if (0 != memcmp(huffstates[i].syms.included, syms.included, - GRPC_CHTTP2_NUM_HUFFSYMS)) - continue; - *isnew = 0; - return i; - } - GPR_ASSERT(nhuffstates != MAXHUFFSTATES); - i = nhuffstates++; - huffstates[i].bitofs = bitofs; - huffstates[i].syms = syms; - huffstates[i].next = nibblelut_empty(); - huffstates[i].emit = nibblelut_empty(); - *isnew = 1; - return i; -} - -/* recursively build a decoding table - - state - the huffman state that we are trying to fill in - nibble - the current nibble - nibbits - the number of bits in the nibble that have been filled in - bitofs - the number of bits of symbol that have been decoded - emit - the symbol to emit on this nibble (or -1 if no symbol has been - found) - syms - the set of symbols that could be matched */ -static void build_dec_tbl(int state, int nibble, int nibbits, unsigned bitofs, - int emit, symset syms) { - int i; - unsigned bit; - - /* If we have four bits in the nibble we're looking at, then we can fill in - a slot in the lookup tables. */ - if (nibbits == 4) { - int isnew; - /* Find the state that we are in: this may be a new state, in which case - we recurse to fill it in, or we may have already seen this state, in - which case the recursion terminates */ - int st = state_index(bitofs, syms, &isnew); - GPR_ASSERT(huffstates[state].next.values[nibble] == -1); - huffstates[state].next.values[nibble] = st; - huffstates[state].emit.values[nibble] = emit; - if (isnew) { - build_dec_tbl(st, 0, 0, bitofs, -1, syms); - } - return; - } - - assert(nsyms(syms)); - - /* A bit can be 0 or 1 */ - for (bit = 0; bit < 2; bit++) { - /* walk over active symbols and see if they have this bit set */ - symset nextsyms = symset_none(); - for (i = 0; i < GRPC_CHTTP2_NUM_HUFFSYMS; i++) { - if (!syms.included[i]) continue; /* disregard inactive symbols */ - if (((grpc_chttp2_huffsyms[i].bits >> - (grpc_chttp2_huffsyms[i].length - bitofs - 1)) & - 1) == bit) { - /* the bit is set, include it in the next recursive set */ - if (grpc_chttp2_huffsyms[i].length == bitofs + 1) { - /* additionally, we've gotten to the end of a symbol - this is a - special recursion step: re-activate all the symbols, reset - bitofs to zero, and recurse */ - build_dec_tbl(state, (nibble << 1) | bit, nibbits + 1, 0, i, - symset_all()); - /* skip the remainder of this loop */ - goto next; - } - nextsyms.included[i] = 1; - } - } - /* recurse down for this bit */ - build_dec_tbl(state, (nibble << 1) | bit, nibbits + 1, bitofs + 1, emit, - nextsyms); - next: - ; - } -} - -static nibblelut ctbl[MAXHUFFSTATES]; -static int nctbl; - -static int ctbl_idx(nibblelut x) { - int i; - for (i = 0; i < nctbl; i++) { - if (0 == memcmp(&x, ctbl + i, sizeof(nibblelut))) return i; - } - ctbl[i] = x; - nctbl++; - return i; -} - -static void dump_ctbl(const char *name) { - int i, j; - printf("static const gpr_int16 %s[%d*16] = {\n", name, nctbl); - for (i = 0; i < nctbl; i++) { - for (j = 0; j < 16; j++) { - printf("%d,", ctbl[i].values[j]); - } - printf("\n"); - } - printf("};\n"); -} - -static void generate_huff_tables(void) { - int i; - build_dec_tbl(state_index(0, symset_all(), &i), 0, 0, 0, -1, symset_all()); - - nctbl = 0; - printf("static const gpr_uint8 next_tbl[%d] = {", nhuffstates); - for (i = 0; i < nhuffstates; i++) { - printf("%d,", ctbl_idx(huffstates[i].next)); - } - printf("};\n"); - dump_ctbl("next_sub_tbl"); - - nctbl = 0; - printf("static const gpr_uint16 emit_tbl[%d] = {", nhuffstates); - for (i = 0; i < nhuffstates; i++) { - printf("%d,", ctbl_idx(huffstates[i].emit)); - } - printf("};\n"); - dump_ctbl("emit_sub_tbl"); -} - -static void generate_base64_huff_encoder_table(void) { - static const char alphabet[] = - "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; - int i; - - printf( - "static const struct { gpr_uint16 bits, gpr_uint8 length } " - "base64_syms[64] = {\n"); - for (i = 0; i < 64; i++) { - printf("{0x%x, %d},", grpc_chttp2_huffsyms[(unsigned char)alphabet[i]].bits, - grpc_chttp2_huffsyms[(unsigned char)alphabet[i]].length); - } - printf("};\n"); -} - -static void generate_base64_inverse_table(void) { - static const char alphabet[] = - "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; - unsigned char inverse[256]; - unsigned i; - - memset(inverse, 255, sizeof(inverse)); - for (i = 0; i < strlen(alphabet); i++) { - inverse[(unsigned char)alphabet[i]] = i; - } - - printf("static const gpr_uint8 inverse_base64[256] = {"); - for (i = 0; i < 256; i++) { - printf("%d,", inverse[i]); - } - printf("};\n"); -} - -int main(void) { - generate_huff_tables(); - generate_first_byte_lut(); - generate_base64_huff_encoder_table(); - generate_base64_inverse_table(); - - return 0; -} |