add browser dist

src/lib/file-id/ComputeHash.ts

@@ -0,0 +1,58 @@
+import {CID_ALGORITHM_CODES, CID_ALGORITHM_NAMES} from "../hash-compute/MultiHashData";
+import {Readable} from "stream";
+import {create} from "multiformats/hashes/digest";
+import {CID} from 'multiformats/cid';
+import {createHasher, codeTable} from "./CreateHasher";
+import {SimpleHash} from "./SimpleHash";
+
+/**
+ * Compute the CIDs of a file using specific algorithms
+ * @param stream The Readable stream of the file
+ * @param algorithms Array of algorithms ('sha256', 'sha1', etc.)
+ * @returns Array of CIDs (in the order of the algorithms)
+ */
+export async function computeCIDs({stream, algorithms}: {
+    stream: Readable | ReadableStream;
+    algorithms: CID_ALGORITHM_NAMES[]
+}): Promise<string[]> {
+    const hashers = hasherDefiner(algorithms);
+
+    // Check if the environment is Node.js or Browser and handle the stream accordingly
+    if (stream instanceof Readable) {
+        // Node.js environment
+        for await (const chunk of stream) {
+            hashers.forEach(item => item.hasher.update(chunk as Buffer));
+        }
+    } else {
+        // Browser environment
+        const reader = stream.getReader();
+        while (true) {
+            const {done, value} = await reader.read();
+            if (done) break;
+            // Assuming the hasher can handle Uint8Array directly
+            hashers.forEach(item => item.hasher.update(Buffer.from(value)));
+        }
+    }
+
+    return cidFinalize(hashers);
+}
+
+function hasherDefiner(algorithms: CID_ALGORITHM_NAMES[]): {
+    hasher: SimpleHash,
+    code: CID_ALGORITHM_CODES
+}[] {
+    const hashers = algorithms.filter(algo => Object.values(CID_ALGORITHM_NAMES).includes(algo))
+        .map(algo => ({
+            hasher: createHasher(algo),
+            code: codeTable[algo]
+        }));
+    return hashers;
+}
+
+async function cidFinalize(hashers: { hasher: SimpleHash, code: number }[]): Promise<string[]> {
+    return await Promise.all(hashers.map(async ({code, hasher}) => {
+        const hashBuffer = hasher.digest();
+        const digest = create(code, hashBuffer);
+        return CID.createV1(code, digest).toString();
+    }));
+}