metalog: add refencode methods for ease-of-use

Summary:
Add application-specific concepts so the callsite does not have to use
low-level APIs.

Reviewed By: muirdm

Differential Revision: D54201003

fbshipit-source-id: 3d713bfc4c56be041f724ae56c6a91922dd08bf0

eden/scm/lib/metalog/src/lib.rs

@@ -13,6 +13,7 @@ pub mod constants;
 mod errors;
 mod export;
 mod metalog;
+mod metalog_ext;
 mod resolve;
 
 pub use errors::Error;

eden/scm/lib/metalog/src/metalog_ext.rs

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This software may be used and distributed according to the terms of the
+ * GNU General Public License version 2.
+ */
+
+//! Extended APIs for application-specific metalog.
+use std::collections::BTreeMap;
+
+use anyhow::Result;
+use types::HgId;
+
+use crate::MetaLog;
+
+impl MetaLog {
+    /// Decode bookmarks.
+    pub fn get_bookmarks(&self) -> Result<BTreeMap<String, HgId>> {
+        let decoded = match self.get("bookmarks")? {
+            Some(data) => refencode::decode_bookmarks(&data)?,
+            None => Default::default(),
+        };
+        Ok(decoded)
+    }
+
+    /// Decode remotenames.
+    pub fn get_remotenames(&self) -> Result<BTreeMap<String, HgId>> {
+        let decoded = match self.get("remotenames")? {
+            Some(data) => refencode::decode_remotenames(&data)?,
+            None => Default::default(),
+        };
+        Ok(decoded)
+    }
+
+    /// Decode visibleheads.
+    pub fn get_visibleheads(&self) -> Result<Vec<HgId>> {
+        let decoded = match self.get("visibleheads")? {
+            Some(data) => refencode::decode_visibleheads(&data)?,
+            None => Default::default(),
+        };
+        Ok(decoded)
+    }
+
+    /// Update bookmarks. This does not write to disk until `commit`.
+    pub fn set_bookmarks(&mut self, value: &BTreeMap<String, HgId>) -> Result<()> {
+        let encoded = refencode::encode_bookmarks(value);
+        self.set("bookmarks", &encoded)?;
+        Ok(())
+    }
+
+    /// Update remotenames. This does not write to disk until `commit`.
+    pub fn set_remotenames(&mut self, value: &BTreeMap<String, HgId>) -> Result<()> {
+        let encoded = refencode::encode_remotenames(value);
+        self.set("remotenames", &encoded)?;
+        Ok(())
+    }
+
+    /// Update visibleheads. This does not write to disk until `commit`.
+    pub fn set_visibleheads(&mut self, value: &[HgId]) -> Result<()> {
+        let encoded = refencode::encode_visibleheads(value);
+        self.set("visibleheads", &encoded)?;
+        Ok(())
+    }
+}