This is an automated email from the ASF dual-hosted git repository.
leirui pushed a commit to branch research/M4-visualization
in repository https://gitbox.apache.org/repos/asf/iotdb.git
The following commit(s) were added to refs/heads/research/M4-visualization by
this push:
new 7f315219ab todo
7f315219ab is described below
commit 7f315219ab1ada8f917ad1a3ab4a337e1bf76aef
Author: Lei Rui <[email protected]>
AuthorDate: Mon Oct 10 11:16:26 2022 +0800
todo
---
.../iotdb/session/MyBasicOperationTest2.java | 120 +++++++++++++++++++++
.../org/apache/iotdb/tsfile/utils/BytesUtils.java | 20 ++++
2 files changed, 140 insertions(+)
diff --git
a/session/src/test/java/org/apache/iotdb/session/MyBasicOperationTest2.java
b/session/src/test/java/org/apache/iotdb/session/MyBasicOperationTest2.java
new file mode 100644
index 0000000000..eed2b00e6e
--- /dev/null
+++ b/session/src/test/java/org/apache/iotdb/session/MyBasicOperationTest2.java
@@ -0,0 +1,120 @@
+package org.apache.iotdb.session;
+
+import java.text.DecimalFormat;
+import java.util.Random;
+import org.apache.commons.math3.stat.descriptive.DescriptiveStatistics;
+import org.apache.iotdb.tsfile.utils.BytesUtils;
+
+public class MyBasicOperationTest2 {
+
+ public static void main(String[] args) {
+ // op1: long v = BytesUtils.bytesToLong(deltaBuf, packWidth * i,
packWidth);
+ // op2: put bytes as a whole into long
+
+ int repeat = 1000000;
+ DescriptiveStatistics op1 = new DescriptiveStatistics();
+ DescriptiveStatistics op2 = new DescriptiveStatistics();
+ for (int k = 0; k < repeat; k++) {
+ // prepare test data
+ Random r = new Random();
+ int low = 0; // inclusive
+ int high = 256; // exclusive
+ int packNum = 128;
+ int packWidth = 8; // equal to one byte length
+ byte[] buf = new byte[packNum];
+ for (int i = 0; i < packNum; i++) {
+ int v = r.nextInt(high - low) + low;
+ BytesUtils.longToBytes(v, buf, i * packWidth, packWidth);
+ }
+
+ // test op1
+ long sum = 0;
+ long start = System.nanoTime();
+ for (int i = 0; i < packNum; i++) {
+ sum += BytesUtils.bytesToLong(buf, packWidth * i, packWidth);
+// System.out.println(BytesUtils.bytesToLong(buf, packWidth * i,
packWidth));
+ }
+ long elapsedTime = System.nanoTime() - start;
+ System.out.println(elapsedTime / 1000.0 + "us");
+ System.out.println(sum);
+ op1.addValue(elapsedTime / 1000.0);
+
+ // test op2
+ sum = 0;
+ start = System.nanoTime();
+ for (int i = 0; i < packNum; i++) {
+ // op2_a:
把一个byte装到一个long里从低位到高位偏移offset，又即byte的最低位在long中的pos（从低到高从0开始数）
+ sum += (buf[i] & 0xff) << 8; // &0xff is to convert bytes to unsigned
bytes
+ // op2_b: 把一个byte的高位x个比特装到一个long的低位x个比特
+ // TODO 如何把一个byte一次分成高位x个比特和低位y个比特
+// System.out.println("---");
+// System.out.println(buf[i]);
+// System.out.println((buf[i] & 0xff & 0b11100000) >> 5);
+ sum += (buf[i] & 0xff & 0b11100000) >> 5;
+
+ // op2_c: 把一个byte的低位y个比特装到一个long的从低位到高位pos=packWidth-1的开始
+// System.out.println((buf[i] & 0xff & ~0b11100000) << 3);
+ sum += (buf[i] & 0xff & ~0b11100000) << 3;
+ }
+ elapsedTime = System.nanoTime() - start;
+ System.out.println(elapsedTime / 1000.0 + "us");
+ System.out.println(sum);
+ op2.addValue(elapsedTime / 1000.0);
+ }
+ printStat(op1, "op1-convertBitToLong");
+ printStat(op2, "op2-compareByte");
+ System.out.println("op1/op2=" + op1.getMean() / op2.getMean());
+ System.out.println("op2/op1=" + op2.getMean() / op1.getMean());
+ }
+
+ private static String printStat(DescriptiveStatistics statistics, String
name) {
+ DecimalFormat df = new DecimalFormat("#,###.00");
+ double max = statistics.getMax();
+ double min = statistics.getMin();
+ double mean = statistics.getMean();
+ double std = statistics.getStandardDeviation();
+ double p25 = statistics.getPercentile(25);
+ double p50 = statistics.getPercentile(50);
+ double p75 = statistics.getPercentile(75);
+ double p90 = statistics.getPercentile(90);
+ double p95 = statistics.getPercentile(95);
+ String res =
+ name
+ + "_stats"
+ + ": "
+ + "num="
+ + statistics.getN()
+ + ", "
+ + "sum="
+ + df.format(statistics.getSum())
+ + "us,"
+ + "mean="
+ + df.format(mean)
+ + ", "
+ + "min="
+ + df.format(min)
+ + ", "
+ + "max="
+ + df.format(max)
+ + ", "
+ + "std="
+ + df.format(std)
+ + ", "
+ + "p25="
+ + df.format(p25)
+ + ", "
+ + "p50="
+ + df.format(p50)
+ + ", "
+ + "p75="
+ + df.format(p75)
+ + ", "
+ + "p90="
+ + df.format(p90)
+ + ", "
+ + "p95="
+ + df.format(p95);
+ System.out.println(res);
+ return res;
+ }
+}
diff --git a/tsfile/src/main/java/org/apache/iotdb/tsfile/utils/BytesUtils.java
b/tsfile/src/main/java/org/apache/iotdb/tsfile/utils/BytesUtils.java
index 2008bd8609..622b228731 100644
--- a/tsfile/src/main/java/org/apache/iotdb/tsfile/utils/BytesUtils.java
+++ b/tsfile/src/main/java/org/apache/iotdb/tsfile/utils/BytesUtils.java
@@ -559,6 +559,26 @@ public class BytesUtils {
return value;
}
+ /**
+ * given a byte array, read width bits from specified pos bits and convert
it to an long.
+ *
+ * @param result input byte array
+ * @param pos bit offset rather than byte offset
+ * @param width bit-width
+ * @return long variable
+ */
+ public static long bytesToLong2(byte[] result, int pos, int width) {
+ long value = 0;
+// int temp = 0;
+// for (int i = 0; i < width; i++) {
+// temp = (pos + width - 1 - i) / 8;
+// value = setLongN(value, i, getByteN(result[temp], pos + width - 1 -
i));
+// }
+ //TODO new implementation
+
+ return value;
+ }
+
/**
* convert eight-bytes byte array cut from parameters to long.
*
