feat(tools): add table manifest command

rust/lance-table/src/io/manifest.rs

@@ -27,15 +27,25 @@ use crate::format::{DataStorageFormat, IndexMetadata, MAGIC, Manifest, Transacti
 
 use super::commit::ManifestLocation;
 
-/// Read Manifest on URI.
+/// Read the raw Manifest protobuf from a URI.
 ///
-/// This only reads manifest files. It does not read data files.
+/// This only reads manifest files. It does not read data files or translate the
+/// protobuf into the semantic [`Manifest`] type.
 #[instrument(level = "debug", skip(object_store))]
-pub async fn read_manifest(
+pub async fn read_manifest_proto(
     object_store: &ObjectStore,
     path: &Path,
     known_size: Option<u64>,
-) -> Result<Manifest> {
+) -> Result<pb::Manifest> {
+    let buf = read_manifest_bytes(object_store, path, known_size).await?;
+    Ok(pb::Manifest::decode(buf)?)
+}
+
+async fn read_manifest_bytes(
+    object_store: &ObjectStore,
+    path: &Path,
+    known_size: Option<u64>,
+) -> Result<Bytes> {
     let file_size = if let Some(known_size) = known_size {
         known_size
     } else {
@@ -52,7 +62,7 @@ pub async fn read_manifest(
     // In case of corruption, the known_size might be wrong. We can retry without
     // the size to be more robust.
     if (buf.len() < 16 || !buf.ends_with(MAGIC)) && known_size.is_some() {
-        return Box::pin(read_manifest(object_store, path, None)).await;
+        return Box::pin(read_manifest_bytes(object_store, path, None)).await;
     }
 
     if buf.len() < 16 {
@@ -104,39 +114,20 @@ pub async fn read_manifest(
         )));
     }
 
-    let proto = pb::Manifest::decode(buf)?;
-    Manifest::try_from(proto)
+    Ok(buf)
 }
 
-#[instrument(level = "debug", skip(object_store, manifest))]
-pub async fn read_manifest_indexes(
+/// Read Manifest on URI.
+///
+/// This only reads manifest files. It does not read data files.
+#[instrument(level = "debug", skip(object_store))]
+pub async fn read_manifest(
     object_store: &ObjectStore,
-    location: &ManifestLocation,
-    manifest: &Manifest,
-) -> Result<Vec<IndexMetadata>> {
-    if let Some(pos) = manifest.index_section.as_ref() {
-        let result = read_index_section(object_store, &location.path, location.size, *pos).await;
-        // A stale cached size makes the index offset fall outside the sized view,
-        // so the read fails as "file size is too small". Retry once with the true
-        // size; surface any other error unchanged.
-        let section = match result {
-            Err(e)
-                if location.size.is_some() && e.to_string().contains("file size is too small") =>
-            {
-                read_index_section(object_store, &location.path, None, *pos).await?
-            }
-            other => other?,
-        };
-
-        let indices = section
-            .indices
-            .into_iter()
-            .map(IndexMetadata::try_from)
-            .collect::<Result<Vec<_>>>()?;
-        Ok(indices)
-    } else {
-        Ok(vec![])
-    }
+    path: &Path,
+    known_size: Option<u64>,
+) -> Result<Manifest> {
+    let proto = read_manifest_proto(object_store, path, known_size).await?;
+    Manifest::try_from(proto)
 }
 
 /// Read the index section message at `pos`, opening the manifest with a known

rust/lance-tools/Cargo.toml

@@ -16,10 +16,13 @@ name = "lance-tools"
 path = "src/main.rs"
 
 [dependencies]
+chrono.workspace = true
 clap = { workspace = true, features = ["derive"] }
 lance-core.workspace = true
 lance-file.workspace = true
 lance-io.workspace = true
+lance-table.workspace = true
 object_store.workspace = true
+prost.workspace = true
 tokio.workspace = true
 url.workspace = true

rust/lance-tools/README.md

@@ -1,3 +1,17 @@
 # lance-tools
 
 `lance-tools` is a command-line tool for interacting with Lance files and tables.
+
+## Commands
+
+Display Lance file footer metadata:
+
+```bash
+lance-tools file meta --source path/to/file.lance
+```
+
+Display a Lance table manifest:
+
+```bash
+lance-tools table manifest --source path/to/table/_versions/1.manifest
+```

rust/lance-tools/src/cli.rs

@@ -20,6 +20,8 @@ pub struct LanceToolsArgs {
 pub enum LanceToolsCommand {
     /// Commands for interacting with Lance files.
     File(LanceFileArgs),
+    /// Commands for interacting with Lance tables.
+    Table(LanceTableArgs),
 }
 
 #[derive(Parser, Debug)]
@@ -34,19 +36,43 @@ pub enum LanceFileCommand {
     Meta(LanceFileMetaArgs),
 }
 
+#[derive(Parser, Debug)]
+pub struct LanceTableArgs {
+    #[command(subcommand)]
+    command: LanceTableCommand,
+}
+
+#[derive(Subcommand, Debug)]
+pub enum LanceTableCommand {
+    /// Display Lance table manifest contents.
+    Manifest(LanceTableManifestArgs),
+}
+
 #[derive(Args, Debug)]
 pub struct LanceFileMetaArgs {
     // The Lance file to examine.
     #[arg(short = 's', long, value_name = "source")]
     pub(crate) source: String,
 }
 
+#[derive(Args, Debug)]
+pub struct LanceTableManifestArgs {
+    /// The Lance manifest file to examine.
+    #[arg(short = 's', long, value_name = "source")]
+    pub(crate) source: String,
+}
+
 impl LanceToolsArgs {
     pub async fn run(&self, writer: impl std::io::Write) -> Result<()> {
         match &self.command {
             LanceToolsCommand::File(args) => match &args.command {
                 LanceFileCommand::Meta(args) => crate::meta::show_file_meta(writer, args).await,
             },
+            LanceToolsCommand::Table(args) => match &args.command {
+                LanceTableCommand::Manifest(args) => {
+                    crate::manifest::show_table_manifest(writer, args).await
+                }
+            },
         }
     }
 }

rust/lance-tools/src/lib.rs

@@ -2,5 +2,6 @@
 // SPDX-FileCopyrightText: Copyright The Lance Authors
 
 pub mod cli;
+pub mod manifest;
 pub mod meta;
 pub mod util;