benchmark batch deletes

tests/benchmark_deletes.nim

@@ -0,0 +1,132 @@
+import os, times, strutils, strformat, random
+import ../leveldbstatic as leveldb
+
+proc benchmarkIndividualDeletes(db: LevelDb, numKeys: int): float =
+  # Insert test data
+  for i in 1..numKeys:
+    let key = "key_" & $i
+    let value = "value_" & $i
+    db.put(key, value)
+  
+  # Benchmark individual deletes
+  let startTime = cpuTime()
+  for i in 1..numKeys:
+    let key = "key_" & $i
+    db.delete(key)
+  let endTime = cpuTime()
+  
+  return endTime - startTime
+
+proc benchmarkBatchDeletes(db: LevelDb, numKeys: int): float =
+  # Insert test data
+  for i in 1..numKeys:
+    let key = "key_" & $i
+    let value = "value_" & $i
+    db.put(key, value)
+  
+  # Benchmark batch deletes
+  let startTime = cpuTime()
+  let batch = newBatch()
+  for i in 1..numKeys:
+    let key = "key_" & $i
+    batch.delete(key)
+  db.write(batch)
+  let endTime = cpuTime()
+  
+  return endTime - startTime
+
+proc benchmarkRandomAccessIndividualDeletes(db: LevelDb, numKeys: int): float =
+  # Insert test data
+  for i in 1..numKeys:
+    let key = "key_" & $i
+    let value = "value_" & $i
+    db.put(key, value)
+  
+  # Create a randomized sequence of keys to delete
+  var keys = newSeq[int](numKeys)
+  for i in 0..<numKeys:
+    keys[i] = i + 1
+  shuffle(keys)
+  
+  # Benchmark individual deletes with random access
+  let startTime = cpuTime()
+  for i in keys:
+    let key = "key_" & $i
+    db.delete(key)
+  let endTime = cpuTime()
+  
+  return endTime - startTime
+
+proc benchmarkRandomAccessBatchDeletes(db: LevelDb, numKeys: int): float =
+  # Insert test data
+  for i in 1..numKeys:
+    let key = "key_" & $i
+    let value = "value_" & $i
+    db.put(key, value)
+  
+  # Create a randomized sequence of keys to delete
+  var keys = newSeq[int](numKeys)
+  for i in 0..<numKeys:
+    keys[i] = i + 1
+  shuffle(keys)
+  
+  # Benchmark batch deletes with random access
+  let startTime = cpuTime()
+  let batch = newBatch()
+  for i in keys:
+    let key = "key_" & $i
+    batch.delete(key)
+  db.write(batch)
+  let endTime = cpuTime()
+  
+  return endTime - startTime
+
+proc runBenchmarks() =
+  let dbName = getTempDir() / "benchmark_deletes"
+  removeDir(dbName)
+  
+  let keyCounts = @[100, 1000, 10000]
+  
+  echo "Benchmarking Individual Deletes vs Batch Deletes"
+  echo "==============================================="
+  echo "Sequential Access:"
+  echo "Key Count      Individual (s)       Batch (s)           Speedup"
+  echo "-----------------------------------------------"
+  
+  for numKeys in keyCounts:
+    # Sequential access benchmark
+    let db1 = leveldb.open(dbName & "_seq1")
+    let individualTime = benchmarkIndividualDeletes(db1, numKeys)
+    db1.close()
+    removeDir(db1.path)
+    
+    let db2 = leveldb.open(dbName & "_seq2")
+    let batchTime = benchmarkBatchDeletes(db2, numKeys)
+    db2.close()
+    removeDir(db2.path)
+    
+    let speedup = individualTime / batchTime
+    echo align($numKeys, 15) & align(formatFloat(individualTime, ffDecimal, 6), 20) & align(formatFloat(batchTime, ffDecimal, 6), 20) & align(formatFloat(speedup, ffDecimal, 2) & "x", 10)
+  
+  echo "\nRandom Access:"
+  echo "Key Count      Individual (s)       Batch (s)           Speedup"
+  echo "-----------------------------------------------"
+  
+  for numKeys in keyCounts:
+    # Random access benchmark
+    let db3 = leveldb.open(dbName & "_rand1")
+    let randomIndividualTime = benchmarkRandomAccessIndividualDeletes(db3, numKeys)
+    db3.close()
+    removeDir(db3.path)
+    
+    let db4 = leveldb.open(dbName & "_rand2")
+    let randomBatchTime = benchmarkRandomAccessBatchDeletes(db4, numKeys)
+    db4.close()
+    removeDir(db4.path)
+    
+    let speedup = randomIndividualTime / randomBatchTime
+    echo align($numKeys, 15) & align(formatFloat(randomIndividualTime, ffDecimal, 6), 20) & align(formatFloat(randomBatchTime, ffDecimal, 6), 20) & align(formatFloat(speedup, ffDecimal, 2) & "x", 10)
+
+when isMainModule:
+  randomize()
+  runBenchmarks()