Backfill and resilver backup store

.github/workflows/rust.yml

@@ -86,6 +86,14 @@ jobs:
         if: "matrix.platform != 'windows-latest'"
         run: |
           RUSTFLAGS="--cfg no_download --cfg cycle_tests --cfg tokio_unstable" cargo test
+      - name: Test tiered storage
+        if: matrix.check-fmt
+        run: |
+          cargo test --lib --features storage-tier io::tier_store
+          RUSTFLAGS="--cfg no_download" cargo test \
+            --features storage-tier \
+            --test integration_tests_rust \
+            builder_configures_sqlite_backup_store
       - name: Test with UniFFI support on Rust ${{ matrix.toolchain }}
         if: "matrix.platform != 'windows-latest' && matrix.build-uniffi"
         run: |

Cargo.toml

@@ -13,7 +13,7 @@ keywords = ["bitcoin", "lightning", "ldk", "bdk"]
 categories = ["cryptography::cryptocurrencies"]
 
 [package.metadata.docs.rs]
-features = ["storage-postgres-vendored-tls"]
+features = ["storage-postgres-vendored-tls", "storage-tier"]
 rustdoc-args = ["--cfg", "docsrs"]
 
 [lib]
@@ -53,6 +53,7 @@ chain-electrum = [
 ]
 chain-bitcoind = ["dep:lightning-block-sync"]
 storage-sqlite = ["dep:rusqlite"]
+storage-tier = ["storage-sqlite"]
 storage-filesystem = ["dep:lightning-persister"]
 storage-vss = ["dep:vss-client", "dep:prost"]
 storage-postgres = ["dep:tokio-postgres", "dep:native-tls", "dep:postgres-native-tls"]

README.md

@@ -78,6 +78,7 @@ LDK Node's optional dependencies are grouped by the functionality they provide:
 | `chain-electrum` | Electrum chain source |
 | `chain-bitcoind` | Bitcoin Core RPC and REST chain source |
 | `storage-sqlite` | SQLite storage |
+| `storage-tier` | Tiered storage with optional ephemeral and backup SQLite stores |
 | `storage-filesystem` | Filesystem storage |
 | `storage-vss` | Versioned Storage Service storage |
 | `storage-postgres` | PostgreSQL storage |
@@ -88,7 +89,8 @@ LDK Node's optional dependencies are grouped by the functionality they provide:
 
 The `default` feature set preserves the native Rust API's previous behavior. It enables all three
 chain sources, SQLite, filesystem and VSS storage, and unified payments. PostgreSQL and UniFFI
-remain opt-in. Every build must enable at least one chain source feature.
+remain opt-in. Tiered storage is also opt-in; enabling `storage-tier` automatically enables
+`storage-sqlite`. Every build must enable at least one chain source feature.
 
 On Linux, `storage-postgres` uses the system OpenSSL installation and requires the OpenSSL
 development headers and `pkg-config`. Enable `storage-postgres-vendored-tls` instead to build