ice: Reverted back change to use Tablemetadata instead of stringBuilder.

Author: subkanthi

ice/src/main/java/com/altinity/ice/internal/cmd/Describe.java

@@ -1,17 +1,17 @@
 package com.altinity.ice.internal.cmd;
 
-import com.fasterxml.jackson.core.JsonParser;
-import com.fasterxml.jackson.databind.JsonNode;
+import com.altinity.ice.internal.model.TableMetadata;
+import com.altinity.ice.internal.model.TableMetadata.*;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.time.Instant;
 import java.time.ZoneId;
 import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
-import java.util.stream.Collectors;
 import org.apache.iceberg.*;
 import org.apache.iceberg.catalog.Namespace;
 import org.apache.iceberg.catalog.TableIdentifier;
@@ -24,12 +24,10 @@ public final class Describe {
 
   private Describe() {}
 
-  // TODO: refactor: the use of StringBuilder below is absolutely criminal
   public static void run(RESTCatalog catalog, String target, boolean json) throws IOException {
     String targetNamespace = null;
     String targetTable = null;
     if (target != null && !target.isEmpty()) {
-      // TODO: support catalog.ns.table
       var s = target.split("[.]", 2);
       switch (s.length) {
         case 2:
@@ -41,8 +39,8 @@ public static void run(RESTCatalog catalog, String target, boolean json) throws
           break;
       }
     }
-    // FIXME: there is no need to list nss/tables when target is given
-    var sb = new StringBuilder();
+
+    List<TableMetadata> tablesMetadata = new ArrayList<>();
     List<Namespace> namespaces = catalog.listNamespaces();
     for (Namespace namespace : namespaces) {
       if (targetNamespace != null && !targetNamespace.equals(namespace.toString())) {
@@ -53,71 +51,55 @@ public static void run(RESTCatalog catalog, String target, boolean json) throws
         if (targetTable != null && !targetTable.equals(tableId.name())) {
           continue;
         }
-        sb.append("---\n");
-        sb.append("kind: Table\n");
-        sb.append("metadata:\n");
-        sb.append("\tid: " + tableId + "\n");
         Table table = catalog.loadTable(tableId);
-        sb.append("data:\n");
-        sb.append("\tschema_raw: |-\n" + prefixEachLine(table.schema().toString(), "\t\t") + "\n");
-        sb.append(
-            "\tpartition_spec_raw: |-\n" + prefixEachLine(table.spec().toString(), "\t\t") + "\n");
-        sb.append(
-            "\tsort_order_raw: |-\n" + prefixEachLine(table.sortOrder().toString(), "\t\t") + "\n");
-        sb.append("\tproperties: \n");
-        for (var property : table.properties().entrySet()) {
-          var v = property.getValue();
-          if (v.contains("\n")) {
-            sb.append("\t\t" + property.getKey() + ": |-\n" + prefixEachLine(v, "\t\t\t") + "\n");
-          } else {
-            sb.append("\t\t" + property.getKey() + ": \"" + v + "\"\n");
-          }
-        }
-        sb.append("\tlocation: " + table.location() + "\n");
-        sb.append("\tcurrent_snapshot: \n");
         Snapshot snapshot = table.currentSnapshot();
+
+        SnapshotInfo snapshotInfo = null;
         if (snapshot != null) {
-          sb.append("\t\tsequence_number: " + snapshot.sequenceNumber() + "\n");
-          sb.append("\t\tid: " + snapshot.snapshotId() + "\n");
-          sb.append("\t\tparent_id: " + snapshot.parentId() + "\n");
-          sb.append("\t\ttimestamp: " + snapshot.timestampMillis() + "\n");
-          sb.append(
-              "\t\ttimestamp_iso: \""
-                  + Instant.ofEpochMilli(snapshot.timestampMillis()).toString()
-                  + "\"\n");
-          sb.append(
-              "\t\ttimestamp_iso_local: \""
-                  + Instant.ofEpochMilli(snapshot.timestampMillis())
+          snapshotInfo =
+              new SnapshotInfo(
+                  snapshot.sequenceNumber(),
+                  snapshot.snapshotId(),
+                  snapshot.parentId(),
+                  snapshot.timestampMillis(),
+                  Instant.ofEpochMilli(snapshot.timestampMillis()).toString(),
+                  Instant.ofEpochMilli(snapshot.timestampMillis())
                       .atZone(ZoneId.systemDefault())
-                      .format(DateTimeFormatter.ISO_OFFSET_DATE_TIME)
-                  + "\"\n");
-          sb.append("\t\toperation: " + snapshot.operation() + "\n");
-          sb.append("\t\tsummary:\n");
-          for (var property : snapshot.summary().entrySet()) {
-            sb.append("\t\t\t" + property.getKey() + ": \"" + property.getValue() + "\"\n");
-          }
-          sb.append("\t\tlocation: " + snapshot.manifestListLocation() + "\n");
+                      .format(DateTimeFormatter.ISO_OFFSET_DATE_TIME),
+                  snapshot.operation(),
+                  snapshot.summary(),
+                  snapshot.manifestListLocation());
         }
 
-        printTableMetrics(table, sb);
+        List<MetricsInfo> metrics = getTableMetrics(table);
+
+        TableData tableData =
+            new TableData(
+                table.schema().toString(),
+                table.spec().toString(),
+                table.sortOrder().toString(),
+                table.properties(),
+                table.location(),
+                snapshotInfo,
+                metrics);
+
+        tablesMetadata.add(new TableMetadata("Table", new Metadata(tableId.toString()), tableData));
       }
     }
-    String r = sb.toString().replace("\t", "  ");
-    if (json) {
-      r = convertYamlToJson(r);
-    }
-    System.out.println(r);
+
+    ObjectMapper mapper = json ? new ObjectMapper() : new ObjectMapper(new YAMLFactory());
+    String output = mapper.writeValueAsString(tablesMetadata);
+    System.out.println(output);
   }
 
-  private static void printTableMetrics(Table table, StringBuilder buffer) throws IOException {
+  private static List<MetricsInfo> getTableMetrics(Table table) throws IOException {
+    List<MetricsInfo> metricsList = new ArrayList<>();
     TableScan scan = table.newScan().includeColumnStats();
     CloseableIterable<FileScanTask> tasks = scan.planFiles();
 
     for (FileScanTask task : tasks) {
       DataFile dataFile = task.file();
-      buffer.append("\tmetrics:\n");
-      buffer.append("\t\tfile: " + dataFile.path() + "\n");
-      buffer.append("\t\trecord_count: " + dataFile.recordCount() + "\n");
+      List<ColumnMetrics> columnMetrics = new ArrayList<>();
 
       Map<Integer, Long> valueCounts = dataFile.valueCounts();
       Map<Integer, Long> nullCounts = dataFile.nullValueCounts();
@@ -128,52 +110,36 @@ private static void printTableMetrics(Table table, StringBuilder buffer) throws
         continue;
       }
 
-      buffer.append("\t\tcolumns:\n");
       for (Types.NestedField field : table.schema().columns()) {
         int id = field.fieldId();
-        buffer.append("\t\t\t" + field.name() + ":\n");
-        if (valueCounts != null) {
-          buffer.append("\t\t\t\tvalue_count: " + valueCounts.get(id) + "\n");
-        }
-        if (nullCounts != null) {
-          buffer.append("\t\t\t\tnull_count: " + nullCounts.get(id) + "\n");
-        }
+        String lowerBound = null;
+        String upperBound = null;
+
         if (lowerBounds != null) {
           ByteBuffer lower = lowerBounds.get(id);
-          String lowerStr =
-              lower != null ? Conversions.fromByteBuffer(field.type(), lower).toString() : "null";
-          buffer.append("\t\t\t\tlower_bound: " + lowerStr + "\n");
+          lowerBound =
+              lower != null ? Conversions.fromByteBuffer(field.type(), lower).toString() : null;
         }
         if (upperBounds != null) {
           ByteBuffer upper = upperBounds.get(id);
-          String upperStr =
-              upper != null ? Conversions.fromByteBuffer(field.type(), upper).toString() : "null";
-          buffer.append("\t\t\t\tupper_bound: " + upperStr + "\n");
+          upperBound =
+              upper != null ? Conversions.fromByteBuffer(field.type(), upper).toString() : null;
         }
-      }
-    }
-
-    tasks.close();
-  }
 
-  private static String convertYamlToJson(String yaml) throws IOException {
-    YAMLFactory yamlFactory = new YAMLFactory();
-    ObjectMapper yamlReader = new ObjectMapper(yamlFactory);
-    ObjectMapper jsonWriter = new ObjectMapper();
-    StringBuilder result = new StringBuilder();
-    try (JsonParser parser = yamlFactory.createParser(yaml)) {
-      while (!parser.isClosed()) {
-        JsonNode node = yamlReader.readTree(parser);
-        if (node != null) {
-          String json = jsonWriter.writeValueAsString(node);
-          result.append(json).append("\n");
-        }
+        columnMetrics.add(
+            new ColumnMetrics(
+                field.name(),
+                valueCounts != null ? valueCounts.get(id) : null,
+                nullCounts != null ? nullCounts.get(id) : null,
+                lowerBound,
+                upperBound));
       }
+
+      metricsList.add(
+          new MetricsInfo(dataFile.path().toString(), dataFile.recordCount(), columnMetrics));
     }
-    return result.toString().trim();
-  }
 
-  private static String prefixEachLine(String v, String prefix) {
-    return v.lines().map(line -> prefix + line).collect(Collectors.joining("\n"));
+    tasks.close();
+    return metricsList;
   }
 }