sheetjs/modules/src/proto.ts

87 lines
2.7 KiB
TypeScript

/*! sheetjs (C) 2013-present SheetJS -- http://sheetjs.com */
type Ptr = [number];
export { Ptr };
/** Parse an integer from the varint that can be exactly stored in a double */
function parse_varint49(buf: Uint8Array, ptr?: Ptr): number {
var l = ptr ? ptr[0] : 0;
var usz = buf[l] & 0x7F;
varint: if(buf[l++] >= 0x80) {
usz |= (buf[l] & 0x7F) << 7; if(buf[l++] < 0x80) break varint;
usz |= (buf[l] & 0x7F) << 14; if(buf[l++] < 0x80) break varint;
usz |= (buf[l] & 0x7F) << 21; if(buf[l++] < 0x80) break varint;
usz += (buf[l] & 0x7F) * Math.pow(2, 28); ++l; if(buf[l++] < 0x80) break varint;
usz += (buf[l] & 0x7F) * Math.pow(2, 35); ++l; if(buf[l++] < 0x80) break varint;
usz += (buf[l] & 0x7F) * Math.pow(2, 42); ++l; if(buf[l++] < 0x80) break varint;
}
if(ptr) ptr[0] = l;
return usz;
}
export { parse_varint49 };
/** Parse a 32-bit signed integer from the raw varint */
function varint_to_i32(buf: Uint8Array): number {
var l = 0, i32 = buf[l] & 0x7F;
varint: if(buf[l++] >= 0x80) {
i32 |= (buf[l] & 0x7F) << 7; if(buf[l++] < 0x80) break varint;
i32 |= (buf[l] & 0x7F) << 14; if(buf[l++] < 0x80) break varint;
i32 |= (buf[l] & 0x7F) << 21; if(buf[l++] < 0x80) break varint;
i32 |= (buf[l] & 0x7F) << 28;
}
return i32;
}
export { varint_to_i32 };
interface ProtoItem {
offset: number;
data: Uint8Array;
}
type ProtoField = Array<ProtoItem>
type ProtoMessage = Array<ProtoField>;
export { ProtoItem, ProtoField, ProtoMessage }
/** Shallow parse of a message */
function parse_shallow(buf: Uint8Array): ProtoMessage {
var out: ProtoMessage = [], ptr: Ptr = [0];
while(ptr[0] < buf.length) {
var off = ptr[0];
var num = parse_varint49(buf, ptr);
var type = num & 0x07; num = Math.floor(num / 8);
var len = 0;
var res: Uint8Array;
if(num == 0) break;
switch(type) {
case 0: {
var l = ptr[0];
while(buf[ptr[0]++] >= 0x80);
res = buf.slice(l, ptr[0]);
} break;
case 5: len = 4;
/* falls through */
case 1: if(!len) len = 8;
/* falls through */
case 2: if(!len) len = parse_varint49(buf, ptr);
res = buf.slice(ptr[0], ptr[0] + len); ptr[0] += len; break;
case 3: // Start group
case 4: // End group
default: throw new Error(`PB Type ${type} for Field ${num} at offset ${off}`);
}
var v: ProtoItem = { offset: off, data: res };
if(out[num] == null) out[num] = [v];
else out[num].push(v);
}
return out;
}
export { parse_shallow };
function mappa<U>(data: ProtoField, cb:(Uint8Array) => U): U[] {
if(!data) return [];
return data.map((d) => { try {
return cb(d.data);
} catch(e) {
var m = e.message?.match(/at offset (\d+)/);
if(m) e.message = e.message.replace(/at offset (\d+)/, "at offset " + (+m[1] + d.offset));
throw e;
}});
}
export { mappa };