From cc271cdcd8792ac27caefcbe45c7349ccd5b5765 Mon Sep 17 00:00:00 2001
From: kungasc <kungasc@yandex-team.com>
Date: Wed, 27 Sep 2023 13:07:12 +0300
Subject: [PATCH] KIKIMR-19139 Load index in Dump

---
 ydb/core/tablet_flat/flat_part_dump.cpp     | 58 ++++++++++++++-------
 ydb/core/tablet_flat/flat_part_index_iter.h |  8 +++
 ydb/core/tablet_flat/flat_table.h           |  2 +-
 3 files changed, 48 insertions(+), 20 deletions(-)

diff --git a/ydb/core/tablet_flat/flat_part_dump.cpp b/ydb/core/tablet_flat/flat_part_dump.cpp
index 456522162041..cb710af7e30b 100644
--- a/ydb/core/tablet_flat/flat_part_dump.cpp
+++ b/ydb/core/tablet_flat/flat_part_dump.cpp
@@ -1,6 +1,6 @@
 #include "flat_part_dump.h"
 #include "flat_part_iface.h"
-#include "flat_page_index.h"
+#include "flat_part_index_iter.h"
 #include "flat_page_data.h"
 #include "flat_page_frames.h"
 #include "flat_page_blobs.h"
@@ -51,10 +51,20 @@ namespace {
         Index(part, depth);
 
         if (depth > 2) {
-            for (auto iter = part.Index->Begin(); iter; ++iter) {
+            auto index = TPartIndexIt(&part, Env, { });
+            
+            for (ssize_t i = 0; ; i++) {
+                auto ready = i == 0 ? index.Seek(0) : index.Next();
+                if (ready != EReady::Data) {
+                    if (ready == EReady::Page) {
+                        Out << " | -- the rest of the index rows aren't loaded" << Endl;
+                    }
+                    break;
+                }
+
                 Out << Endl;
 
-                DataPage(part, iter->GetPageId());
+                DataPage(part, index.GetPageId());
             }
         }
     }
@@ -90,15 +100,21 @@ namespace {
     {
         Key.reserve(part.Scheme->Groups[0].KeyTypes.size());
 
-        auto label = part.Index.Label();
-
-        const auto items = (part.Index->End() - part.Index->Begin() + 1);
+        auto index = TPartIndexIt(&part, Env, { });
+        auto label = index.TryGetLabel();
 
-        Out
-            << " + Index{" << (ui16)label.Type << " rev "
-            << label.Format << ", " << label.Size << "b}"
-            << " " << items << " rec" << Endl
-            << " |  Page     Row    Bytes  (";
+        if (label) {
+            Out
+                << " + Index{" << (ui16)label->Type << " rev "
+                << label->Format << ", " << label->Size << "b}"
+                << Endl
+                << " |  Page     Row    Bytes  (";
+        } else {
+            Out
+                << " + Index{unknown}"
+                << Endl
+                << " |  Page     Row    Bytes  (";
+        }
 
         for (auto off : xrange(part.Scheme->Groups[0].KeyTypes.size())) {
             Out << (off ? ", " : "");
@@ -108,20 +124,24 @@ namespace {
 
         Out << ")" << Endl;
 
-        ssize_t seen = 0;
-
-        for (ssize_t i = 0; i < items; i++) {
+        for (ssize_t i = 0; ; i++) {
             Key.clear();
 
-            if (depth < 2 && (seen += 1) > 10) {
-                Out
-                    << " | -- skipped " << (items - Min(items, seen - 1))
-                    << " entries, depth level " << depth << Endl;
+            if (depth < 2 && i >= 10) {
+                Out << " | -- skipped the rest entries, depth level " << depth << Endl;
+                break;
+            }
 
+            // prints without LastKeyRecord, but it seems ok for now
+            auto ready = i == 0 ? index.Seek(0) : index.Next();
+            if (ready != EReady::Data) {
+                if (ready == EReady::Page) {
+                    Out << " | -- the rest of the index rows aren't loaded" << Endl;
+                }
                 break;
             }
 
-            auto record = part.Index.At(i);
+            auto record = index.GetRecord();
             for (const auto &info: part.Scheme->Groups[0].ColsKeyIdx)
                 Key.push_back(record->Cell(info));
 
diff --git a/ydb/core/tablet_flat/flat_part_index_iter.h b/ydb/core/tablet_flat/flat_part_index_iter.h
index 23e133a3575e..07e886e497bf 100644
--- a/ydb/core/tablet_flat/flat_part_index_iter.h
+++ b/ydb/core/tablet_flat/flat_part_index_iter.h
@@ -98,6 +98,14 @@ class TPartIndexIt {
         return TryGetIndex();
     }
 
+    std::optional<NPage::TLabel> TryGetLabel() {
+        auto index = TryGetIndex();
+        if (!index) {
+            return { };
+        }
+        return index->Label();
+    }
+
 public:
     TRowId GetEndRowId() const {
         return EndRowId;
diff --git a/ydb/core/tablet_flat/flat_table.h b/ydb/core/tablet_flat/flat_table.h
index 71fd8ffdb304..0b0cf7963933 100644
--- a/ydb/core/tablet_flat/flat_table.h
+++ b/ydb/core/tablet_flat/flat_table.h
@@ -303,7 +303,7 @@ class TTable: public TAtomicRefCount<TTable> {
         for (const auto& flat : Flatten) {
             if (const TPartView &partView = flat.second) {
                 size += partView->DataSize();
-                rows += partView->Index.Rows();
+                rows += partView.Part->Stat.Rows;
             }
         }