Add a new command to nimble_dump: stripe_groups_metadata (#133)

Summary:
Pull Request resolved: #133

`stripe_groups_metadata` dumps the stripes metadata information as referenced by the footer: https://www.internalfb.com/code/fbsource/[3a9c4e4b1b7b7e7b22668f54ddc12f0ccfc904b4]/fbcode/dwio/nimble/tablet/Footer.fbs?lines=52

Reviewed By: helfman

Differential Revision: D68035171

fbshipit-source-id: 388428157144ab03e3f2af15a158b65ad9f00b2b

dwio/nimble/tools/NimbleDump.cpp

@@ -339,6 +339,31 @@ int main(int argc, char* argv[]) {
         );
   // clang-format on
 
+  app.addCommand(
+         "stripe_groups_metadata",
+         "<file>",
+         "Print stripe groups metadata information",
+         "Prints stripe groups information as referenced by the footer.",
+         [](const po::variables_map& options,
+            const std::vector<std::string>& /*args*/) {
+           nimble::tools::NimbleDumpLib{
+               std::cout, options["file"].as<std::string>()}
+               .emitStripeGroupsMetadata(options["no_header"].as<bool>());
+         },
+         positionalArgs)
+      // clang-format off
+        .add_options()
+        (
+            "file",
+            po::value<std::string>()->required(),
+            "Nimble file path. Can be a local path or a Warm Storage path."
+        )(
+            "no_header,n",
+            po::bool_switch()->default_value(false),
+            "Don't print column names. Default is to include column names."
+        );
+  // clang-format on
+
   app.addAlias("i", "info");
   app.addAlias("b", "binary");
   app.addAlias("c", "content");

dwio/nimble/tools/NimbleDumpLib.cpp

@@ -886,4 +886,27 @@ void NimbleDumpLib::emitStripesMetadata(bool noHeader) {
   });
 }
 
+void NimbleDumpLib::emitStripeGroupsMetadata(bool noHeader) {
+  TabletReader tabletReader{*pool_, file_.get()};
+  TableFormatter formatter(
+      ostream_,
+      {
+          {"Group Id", 10, Alignment::Left},
+          {"Offset", 15, Alignment::Left},
+          {"Size", 15, Alignment::Left},
+          {"Compression Type", 18, Alignment::Left},
+      },
+      noHeader);
+  auto stripeGroupsMetadata = tabletReader.stripeGroupsMetadata();
+  for (auto i = 0; i < stripeGroupsMetadata.size(); ++i) {
+    const auto& metadata = stripeGroupsMetadata[i];
+    formatter.writeRow({
+        commaSeparated(i),
+        commaSeparated(metadata.offset()),
+        commaSeparated(metadata.size()),
+        toString(metadata.compressionType()),
+    });
+  }
+}
+
 } // namespace facebook::nimble::tools

dwio/nimble/tools/NimbleDumpLib.h

@@ -44,6 +44,7 @@ class NimbleDumpLib {
       uint32_t stripeId);
   void emitLayout(bool noHeader, bool compressed);
   void emitStripesMetadata(bool noHeader);
+  void emitStripeGroupsMetadata(bool noHeader);
 
  private:
   std::shared_ptr<velox::memory::MemoryPool> pool_;