function packFrame(item) {
var length = item.body.length;
// write TYPE_AND_BASE128_SIZE
var head = [(typeToNum[item.type] << 4) | (length & 0xf)];
var i = 0;
length >>= 4;
while (length) {
head[i++] |= 0x80;
head[i] = length & 0x7f;
length >>= 7;
}
if (typeof item.ref === "number") {
// write BIG_ENDIAN_MODIFIED_BASE_128_NUMBER
var offset = item.ref;
// Calculate how many digits we need in base 128 and move the pointer
i += Math.floor(Math.log(offset) / Math.log(0x80)) + 1;
// Write the last digit
head[i] = offset & 0x7f;
// Then write the rest
while (offset >>= 7) {
head[--i] = 0x80 | (--offset & 0x7f);
}
}
var parts = [bodec.fromArray(head)];
if (typeof item.ref === "string") {
parts.push(bodec.fromHex(item.ref));
}
parts.push(deflate(item.body));
return bodec.join(parts);
}
return function (item) {
if (item === undefined) {
if (left !== 0) throw new Error("Some items were missing");
return emit();
}
if (typeof item.num === "number") {
if (left !== undefined) throw new Error("Header already sent");
left = item.num;
write(packHeader(item.num));
}
else if (typeof item.type === "string" && bodec.isBinary(item.body)) {
// The header must be sent before items.
if (typeof left !== "number") throw new Error("Headers not sent yet");
// Make sure we haven't sent all the items already
if (!left) throw new Error("All items already sent");
// Send the item in packstream format
write(packFrame(item));
// Send the checksum after the last item
if (!--left) {
emit(bodec.fromHex(sha1sum.digest()));
}
}
else {
throw new Error("Invalid item");
}
};