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/*
* Bitstream encoder.
*/
#include "duk_internal.h"
DUK_INTERNAL void duk_be_encode(duk_bitencoder_ctx *ctx, duk_uint32_t data, duk_small_int_t bits) {
duk_uint8_t tmp;
DUK_ASSERT(ctx != NULL);
DUK_ASSERT(ctx->currbits < 8);
/* This limitation would be fixable but adds unnecessary complexity. */
DUK_ASSERT(bits >= 1 && bits <= 24);
ctx->currval = (ctx->currval << bits) | data;
ctx->currbits += bits;
while (ctx->currbits >= 8) {
if (ctx->offset < ctx->length) {
tmp = (duk_uint8_t) ((ctx->currval >> (ctx->currbits - 8)) & 0xff);
ctx->data[ctx->offset++] = tmp;
} else {
/* If buffer has been exhausted, truncate bitstream */
ctx->truncated = 1;
}
ctx->currbits -= 8;
}
}
DUK_INTERNAL void duk_be_finish(duk_bitencoder_ctx *ctx) {
duk_small_int_t npad;
DUK_ASSERT(ctx != NULL);
DUK_ASSERT(ctx->currbits < 8);
npad = (duk_small_int_t) (8 - ctx->currbits);
if (npad > 0) {
duk_be_encode(ctx, 0, npad);
}
DUK_ASSERT(ctx->currbits == 0);
}
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