refactor: common base library (#1780)

## Description

This adds a new crate `iroh_base`. The following types were moved into
the new crate:

* `Hash`, `HashAndFormat` and `BlobFormat` from `iroh_bytes::util`
* `base32` encoding/decoding util functions. They lived at various
places before.
* `RpcError` and `RpcResult` from `iroh_bytes::util`

## Notes & open questions

* Naming: Shall it be `iroh_common` or `iroh_base`? I do not mind. If
anyhow has a preference, please raise. I can change easily.
* Anything else that should be moved over? Anything that I moved that
should *not* be moved?

## Change checklist

- [ ] Self-review.
- [ ] Documentation updates if relevant.
- [ ] Tests if relevant.

---------

Co-authored-by: Asmir Avdicevic <asmir.avdicevic64@gmail.com>

Cargo.toml

@@ -2,6 +2,7 @@
 members = [
   "iroh",
   "iroh-bytes",
+  "iroh-base",
   "iroh-gossip",
   "iroh-metrics",
   "iroh-net",

iroh-base/Cargo.toml

@@ -0,0 +1,37 @@
+[package]
+name = "iroh-base"
+version = "0.10.0"
+edition = "2021"
+readme = "README.md"
+description = "base type and utilities for Iroh"
+license = "MIT OR Apache-2.0"
+authors = ["n0 team"]
+repository = "https://github.com/n0-computer/iroh"
+
+# Sadly this also needs to be updated in .github/workflows/ci.yml
+rust-version = "1.72"
+
+[lints]
+workspace = true
+
+[dependencies]
+anyhow = { version = "1", features = ["backtrace"] }
+bao-tree = { version = "0.9.1", features = ["tokio_fsm"], default-features = false, optional = true }
+data-encoding = { version = "2.3.3", optional = true }
+hex = "0.4.3"
+multibase = { version = "0.9.1", optional = true }
+postcard = { version = "1", default-features = false, features = ["alloc", "use-std", "experimental-derive"], optional = true }
+serde = { version = "1", features = ["derive"] }
+serde-error = "0.1.2"
+thiserror = "1"
+
+[dev-dependencies]
+iroh-test = { path = "../iroh-test" }
+proptest = "1.0.0"
+serde_json = "1.0.107"
+serde_test = "1.0.176"
+
+[features]
+default = ["hash", "base32"]
+hash = ["bao-tree", "multibase", "data-encoding", "postcard"]
+base32 = ["data-encoding"]

iroh-base/README.md

@@ -0,0 +1,21 @@
+# iroh-base
+
+This crate provides base types and utilities used throughout Iroh.
+
+# License
+
+This project is licensed under either of
+
+ * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
+   http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license ([LICENSE-MIT](LICENSE-MIT) or
+   http://opensource.org/licenses/MIT)
+
+at your option.
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in this project by you, as defined in the Apache-2.0 license,
+shall be dual licensed as above, without any additional terms or conditions.
+

iroh-base/src/base32.rs

@@ -0,0 +1,40 @@
+pub use data_encoding::{DecodeError, DecodeKind};
+
+/// Convert to a base32 string
+pub fn fmt(bytes: impl AsRef<[u8]>) -> String {
+    let mut text = data_encoding::BASE32_NOPAD.encode(bytes.as_ref());
+    text.make_ascii_lowercase();
+    text
+}
+
+/// Convert to a base32 string and append out `out`
+pub fn fmt_append(bytes: impl AsRef<[u8]>, out: &mut String) {
+    let start = out.len();
+    data_encoding::BASE32_NOPAD.encode_append(bytes.as_ref(), out);
+    let end = out.len();
+    out[start..end].make_ascii_lowercase();
+}
+
+/// Convert to a base32 string limited to the first 10 bytes
+pub fn fmt_short(bytes: impl AsRef<[u8]>) -> String {
+    let len = bytes.as_ref().len().min(10);
+    let mut text = data_encoding::BASE32_NOPAD.encode(&bytes.as_ref()[..len]);
+    text.make_ascii_lowercase();
+    text
+}
+
+/// Parse from a base32 string into a byte array
+pub fn parse_array<const N: usize>(input: &str) -> Result<[u8; N], DecodeError> {
+    data_encoding::BASE32_NOPAD
+        .decode(input.to_ascii_uppercase().as_bytes())?
+        .try_into()
+        .map_err(|_| DecodeError {
+            position: N,
+            kind: DecodeKind::Length,
+        })
+}
+
+/// Decode form a base32 string to a vector of bytes
+pub fn parse_vec(input: &str) -> Result<Vec<u8>, DecodeError> {
+    data_encoding::BASE32_NOPAD.decode(input.to_ascii_uppercase().as_bytes())
+}