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node_modules/multiformats/src/hashes/interface.ts

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+// # Multihash
+
+/**
+ * Represents a multihash digest which carries information about the
+ * hashing algorithm and an actual hash digest.
+ */
+// Note: In the current version there is no first class multihash
+// representation (plain Uint8Array is used instead) instead there seems to be
+// a bunch of places that parse it to extract (code, digest, size). By creating
+// this first class representation we avoid reparsing and things generally fit
+// really nicely.
+export interface MultihashDigest<Code extends number = number> {
+  /**
+   * Code of the multihash
+   */
+  code: Code
+
+  /**
+   * Raw digest (without a hashing algorithm info)
+   */
+  digest: Uint8Array
+
+  /**
+   * byte length of the `this.digest`
+   */
+  size: number
+
+  /**
+   * Binary representation of this multihash digest.
+   */
+  bytes: Uint8Array
+}
+
+/**
+ * Hasher represents a hashing algorithm implementation that produces as
+ * `MultihashDigest`.
+ */
+export interface MultihashHasher<Code extends number = number> {
+  /**
+   * Takes binary `input` and returns it (multi) hash digest. Return value is
+   * either promise of a digest or a digest. This way general use can `await`
+   * while performance critical code may asses return value to decide whether
+   * await is needed.
+   */
+  digest(input: Uint8Array): Promise<MultihashDigest<Code>> | MultihashDigest<Code>
+
+  /**
+   * Name of the multihash
+   */
+  name: string
+
+  /**
+   * Code of the multihash
+   */
+  code: Code
+}
+
+/**
+ * Sync variant of `MultihashHasher` that refines return type of the `digest`
+ * to `MultihashDigest`. It is subtype of `MultihashHasher` so implementations
+ * of this interface can be passed anywhere `MultihashHasher` is expected,
+ * allowing consumer to either `await` or check the return type to decide
+ * whether to await or proceed with return value.
+ *
+ * `SyncMultihashHasher` is useful in certain APIs where async hashing would be
+ * impractical e.g. implementation of Hash Array Mapped Trie (HAMT).
+ */
+export interface SyncMultihashHasher<Code extends number = number> extends MultihashHasher<Code> {
+  digest(input: Uint8Array): MultihashDigest<Code>
+}