Initial import

third_party/duktape/duk_util_bitencoder.c

@@ -0,0 +1,43 @@
+/*
+ *  Bitstream encoder.
+ */
+
+#include "third_party/duktape/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);
+}