@eagleoutice/flowr-dev/project/sigdb/hash.js

Static Dataflow Analyzer and Program Slicer for the R Programming Language

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.hashOf = hashOf;
exports.contentHash = contentHash;
exports.dictionaryHash = dictionaryHash;
exports.shardHash = shardHash;
/**
 * Stable content hashes over a bundle's data, used both when writing a bundle (to stamp its header/manifest)
 * and when reading one back (to verify it). A portable {@link Hash53} runs over newline-terminated JSON chunks
 * so chunk boundaries can never collide. Split out of `../sigdb` as it is shared by the writer and the reader.
 */
const hash_1 = require("../../util/hash");
const decode_1 = require("./decode");
/** the JSON chunks a bundle is hashed over: every dictionary string, every blob tuple, then the pkgs + meta maps */
function* hashChunks(db) {
    for (const s of db.strings) {
        yield JSON.stringify(s);
    }
    for (const b of db.blobs) {
        yield JSON.stringify((0, decode_1.blobTuple)(b));
    }
    yield JSON.stringify(db.pkgs);
    yield JSON.stringify(db.meta);
}
/** run a Hash53 over a stream of chunks (each null-terminated so boundaries can't collide) */
function hashOf(chunks) {
    const h = new hash_1.Hash53();
    for (const chunk of chunks) {
        h.update(chunk).update('\x00');
    }
    return h.digest();
}
/** the self-contained content hash of a whole bundle (dictionary + blobs + routing/metadata) */
function contentHash(db) {
    return hashOf(hashChunks(db));
}
/** stable hash of a shared dictionary */
function dictionaryHash(strings) {
    return hashOf((function* () {
        for (const s of strings) {
            yield JSON.stringify(s);
        }
    })());
}
/** stable hash of one shard's data (its blobs + pkgs map; the dictionary is hashed separately) */
function shardHash(blobs, pkgs) {
    return hashOf((function* () {
        for (const b of blobs) {
            yield JSON.stringify((0, decode_1.blobTuple)(b));
        }
        yield JSON.stringify(pkgs);
    })());
}
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