stats corrections minor additions

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>com.tidesdb</groupId>
     <artifactId>tidesdb-java</artifactId>
-    <version>0.3.0</version>
+    <version>0.3.1</version>
     <packaging>jar</packaging>
 
     <name>TidesDB Java</name>

src/main/c/com_tidesdb_TidesDB.c

@@ -431,13 +431,27 @@ JNIEXPORT jobject JNICALL Java_com_tidesdb_ColumnFamily_nativeGetStats(JNIEnv *e
         free(nums);
     }
 
-    jclass statsClass = (*env)->FindClass(env, "com/tidesdb/Stats");
-    jmethodID constructor =
-        (*env)->GetMethodID(env, statsClass, "<init>", "(IJ[J[ILcom/tidesdb/ColumnFamilyConfig;)V");
+    jlongArray levelKeyCounts = (*env)->NewLongArray(env, stats->num_levels);
+    if (stats->level_key_counts != NULL)
+    {
+        jlong *counts = malloc(stats->num_levels * sizeof(jlong));
+        for (int i = 0; i < stats->num_levels; i++)
+        {
+            counts[i] = (jlong)stats->level_key_counts[i];
+        }
+        (*env)->SetLongArrayRegion(env, levelKeyCounts, 0, stats->num_levels, counts);
+        free(counts);
+    }
 
-    jobject statsObj =
-        (*env)->NewObject(env, statsClass, constructor, stats->num_levels,
-                          (jlong)stats->memtable_size, levelSizes, levelNumSSTables, NULL);
+    jclass statsClass = (*env)->FindClass(env, "com/tidesdb/Stats");
+    jmethodID constructor = (*env)->GetMethodID(env, statsClass, "<init>",
+                                                "(IJ[J[ILcom/tidesdb/ColumnFamilyConfig;JJDD[JDD)V");
+
+    jobject statsObj = (*env)->NewObject(env, statsClass, constructor, stats->num_levels,
+                                         (jlong)stats->memtable_size, levelSizes, levelNumSSTables,
+                                         NULL, (jlong)stats->total_keys, (jlong)stats->total_data_size,
+                                         stats->avg_key_size, stats->avg_value_size, levelKeyCounts,
+                                         stats->read_amp, stats->hit_rate);
 
     tidesdb_free_stats(stats);
 

src/main/java/com/tidesdb/Stats.java

@@ -28,13 +28,30 @@ public class Stats {
     private final long[] levelSizes;
     private final int[] levelNumSSTables;
     private final ColumnFamilyConfig config;
+    private final long totalKeys;
+    private final long totalDataSize;
+    private final double avgKeySize;
+    private final double avgValueSize;
+    private final long[] levelKeyCounts;
+    private final double readAmp;
+    private final double hitRate;
 
-    public Stats(int numLevels, long memtableSize, long[] levelSizes, int[] levelNumSSTables, ColumnFamilyConfig config) {
+    public Stats(int numLevels, long memtableSize, long[] levelSizes, int[] levelNumSSTables, 
+                 ColumnFamilyConfig config, long totalKeys, long totalDataSize, 
+                 double avgKeySize, double avgValueSize, long[] levelKeyCounts,
+                 double readAmp, double hitRate) {
         this.numLevels = numLevels;
         this.memtableSize = memtableSize;
         this.levelSizes = levelSizes;
         this.levelNumSSTables = levelNumSSTables;
         this.config = config;
+        this.totalKeys = totalKeys;
+        this.totalDataSize = totalDataSize;
+        this.avgKeySize = avgKeySize;
+        this.avgValueSize = avgValueSize;
+        this.levelKeyCounts = levelKeyCounts;
+        this.readAmp = readAmp;
+        this.hitRate = hitRate;
     }
 
     /**
@@ -82,11 +99,80 @@ public ColumnFamilyConfig getConfig() {
         return config;
     }
 
+    /**
+     * Gets the total number of keys across memtable and all SSTables.
+     *
+     * @return total key count
+     */
+    public long getTotalKeys() {
+        return totalKeys;
+    }
+
+    /**
+     * Gets the total data size (klog + vlog) across all SSTables.
+     *
+     * @return total data size in bytes
+     */
+    public long getTotalDataSize() {
+        return totalDataSize;
+    }
+
+    /**
+     * Gets the average key size in bytes.
+     *
+     * @return average key size
+     */
+    public double getAvgKeySize() {
+        return avgKeySize;
+    }
+
+    /**
+     * Gets the average value size in bytes.
+     *
+     * @return average value size
+     */
+    public double getAvgValueSize() {
+        return avgValueSize;
+    }
+
+    /**
+     * Gets the number of keys per level.
+     *
+     * @return array of key counts per level
+     */
+    public long[] getLevelKeyCounts() {
+        return levelKeyCounts;
+    }
+
+    /**
+     * Gets the read amplification (point lookup cost multiplier).
+     *
+     * @return read amplification factor
+     */
+    public double getReadAmp() {
+        return readAmp;
+    }
+
+    /**
+     * Gets the cache hit rate for this column family.
+     *
+     * @return hit rate (0.0 to 1.0), or 0.0 if cache is disabled
+     */
+    public double getHitRate() {
+        return hitRate;
+    }
+
     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();
         sb.append("Stats{numLevels=").append(numLevels);
         sb.append(", memtableSize=").append(memtableSize);
+        sb.append(", totalKeys=").append(totalKeys);
+        sb.append(", totalDataSize=").append(totalDataSize);
+        sb.append(", avgKeySize=").append(avgKeySize);
+        sb.append(", avgValueSize=").append(avgValueSize);
+        sb.append(", readAmp=").append(readAmp);
+        sb.append(", hitRate=").append(hitRate);
         if (levelSizes != null) {
             sb.append(", levelSizes=[");
             for (int i = 0; i < levelSizes.length; i++) {
@@ -103,6 +189,14 @@ public String toString() {
             }
             sb.append("]");
         }
+        if (levelKeyCounts != null) {
+            sb.append(", levelKeyCounts=[");
+            for (int i = 0; i < levelKeyCounts.length; i++) {
+                if (i > 0) sb.append(", ");
+                sb.append(levelKeyCounts[i]);
+            }
+            sb.append("]");
+        }
         sb.append("}");
         return sb.toString();
     }