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#include <stdio.h>
#include "zbuild.h"
#include "zutil.h"
#include "inftrees.h"
#include "inflate.h"
// Build and return state with length and distance decoding tables and index sizes set to fixed code decoding.
void Z_INTERNAL buildfixedtables(struct inflate_state *state) {
static code *lenfix, *distfix;
static code fixed[544];
// build fixed huffman tables
unsigned sym, bits;
static code *next;
// literal/length table
sym = 0;
while (sym < 144) state->lens[sym++] = 8;
while (sym < 256) state->lens[sym++] = 9;
while (sym < 280) state->lens[sym++] = 7;
while (sym < 288) state->lens[sym++] = 8;
next = fixed;
lenfix = next;
bits = 9;
zng_inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
// distance table
sym = 0;
while (sym < 32) state->lens[sym++] = 5;
distfix = next;
bits = 5;
zng_inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
state->lencode = lenfix;
state->lenbits = 9;
state->distcode = distfix;
state->distbits = 5;
}
// Create fixed tables on the fly and write out a inffixed_tbl.h file that is #include'd above.
// makefixed() writes those tables to stdout, which would be piped to inffixed_tbl.h.
void makefixed(void) {
unsigned low, size;
struct inflate_state state;
memset(&state, 0, sizeof(state));
buildfixedtables(&state);
puts("/* inffixed_tbl.h -- table for decoding fixed codes");
puts(" * Generated automatically by makefixed().");
puts(" */");
puts("");
puts("/* WARNING: this file should *not* be used by applications.");
puts(" * It is part of the implementation of this library and is");
puts(" * subject to change. Applications should only use zlib.h.");
puts(" */");
puts("");
size = 1U << 9;
printf("static const code lenfix[%u] = {", size);
low = 0;
for (;;) {
if ((low % 7) == 0)
printf("\n ");
printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
state.lencode[low].bits, state.lencode[low].val);
if (++low == size)
break;
putchar(',');
}
puts("\n};");
size = 1U << 5;
printf("\nstatic const code distfix[%u] = {", size);
low = 0;
for (;;) {
if ((low % 6) == 0)
printf("\n ");
printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits, state.distcode[low].val);
if (++low == size)
break;
putchar(',');
}
puts("\n};");
}
// The output of this application can be piped out to recreate inffixed_tbl.h
int main(void) {
makefixed();
return 0;
}
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