From 08d24b059a35e33d8a0ae778621ebd18b9f17e8f Mon Sep 17 00:00:00 2001
From: zzz <zzz@mail.i2p>
Date: Tue, 18 Jan 2011 14:05:26 +0000
Subject: [PATCH] remove nativeDoubleValue(), update jbigi README
---
core/c/jbigi/README | 12 ++-
core/c/jbigi/jbigi/src/jbigi.c | 27 -------
.../src/net/i2p/util/NativeBigInteger.java | 80 +------------------
3 files changed, 15 insertions(+), 104 deletions(-)
diff --git a/core/c/jbigi/README b/core/c/jbigi/README
index 56560a94f1..b95ee78fed 100644
--- a/core/c/jbigi/README
+++ b/core/c/jbigi/README
@@ -9,9 +9,19 @@ TODO: Document generated folder structure
TODO: Instructions for adding the libraries to a jar
Linux-specific information:
+===========================
Some linux distributions comes bundled with GMP.
-There is currently no out-of-the-box support for this in the current build-scripts.
+Try 'locate lib/libgmp.so' to see.
+If so, install the the libgmp3-dev debian package to get the libgmp headers.
+Then export I2P=/path/to/your/i2p/install.
+Then do 'build.sh dynamic'. This will do a quick build using your installed libgmp library
+and then test it and the jbigi in your I2P installation to see which is faster.
+
+If the new jbigi is slower, then run 'build.sh' (without the 'dynamic'), which will download
+the 4.3.1 libgmp library, build, and test that.
+
Windows-specific information:
+=============================
The best way of building the jbigi dll's is to install Mingw {URL} and msys {URL}.
The combination of these two should be able to run the included build-scripts without modifications.
diff --git a/core/c/jbigi/jbigi/src/jbigi.c b/core/c/jbigi/jbigi/src/jbigi.c
index b0d702310d..f605c6a0ea 100644
--- a/core/c/jbigi/jbigi/src/jbigi.c
+++ b/core/c/jbigi/jbigi/src/jbigi.c
@@ -57,33 +57,6 @@ JNIEXPORT jbyteArray JNICALL Java_net_i2p_util_NativeBigInteger_nativeModPow
return jresult;
}
-/******** nativeDoubleValue() */
-/*
- * Class: net_i2p_util_NativeBigInteger
- * Method: nativeDoubleValue
- * Signature: ([B)D
- *
- * From the Javadoc:
- *
- * Converts a BigInteger byte-array to a 'double'
- * @param ba Big endian twos complement representation of the BigInteger to convert to a double
- * @return The plain double-value represented by 'ba'
- */
-JNIEXPORT jdouble JNICALL Java_net_i2p_util_NativeBigInteger_nativeDoubleValue
-(JNIEnv * env, jclass cls, jbyteArray jba){
- /* 1) Convert the bytearray BigInteger value into the format libgmp understands
- * 2) Call libgmp's mpz_get_d.
- * 3) Convert libgmp's result into a big endian twos complement number.
- */
- mpz_t mval;
- jdouble retval;
- convert_j2mp(env, jba, &mval);
-
- retval = mpz_get_d(mval);
- mpz_clear(mval);
- return retval;
-}
-
/******************************
*****Conversion methods*******
******************************/
diff --git a/core/java/src/net/i2p/util/NativeBigInteger.java b/core/java/src/net/i2p/util/NativeBigInteger.java
index 9e98c5855f..8c41746f41 100644
--- a/core/java/src/net/i2p/util/NativeBigInteger.java
+++ b/core/java/src/net/i2p/util/NativeBigInteger.java
@@ -28,8 +28,7 @@ import net.i2p.I2PAppContext;
/**
* <p>BigInteger that takes advantage of the jbigi library for the modPow operation,
* which accounts for a massive segment of the processing cost of asymmetric
- * crypto. It also takes advantage of the jbigi library for converting a BigInteger
- * value to a double. Sun's implementation of the 'doubleValue()' method is _very_ lousy.
+ * crypto.
*
* The jbigi library itself is basically just a JNI wrapper around the
* GMP library - a collection of insanely efficient routines for dealing with
@@ -64,7 +63,7 @@ import net.i2p.I2PAppContext;
* "net/i2p/util/jbigi-windows-none.dll").</p>
*
* <p>Running this class by itself does a basic unit test and benchmarks the
- * NativeBigInteger.modPow/doubleValue vs. the BigInteger.modPow/doubleValue by running a 2Kbit op 100
+ * NativeBigInteger.modPow vs. the BigInteger.modPow by running a 2Kbit op 100
* times. At the end of each test, if the native implementation is loaded this will output
* something like:</p>
* <pre>
@@ -194,14 +193,6 @@ public class NativeBigInteger extends BigInteger {
*/
public native static byte[] nativeModPow(byte base[], byte exponent[], byte modulus[]);
- /**
- * Converts a BigInteger byte-array to a 'double'
- * @param ba Big endian twos complement representation of the BigInteger to convert to a double
- * @return The plain double-value represented by 'ba'
- * @deprecated unused
- */
- public native static double nativeDoubleValue(byte ba[]);
-
private byte[] cachedBa;
public NativeBigInteger(byte[] val) {
@@ -250,12 +241,9 @@ public class NativeBigInteger extends BigInteger {
return cachedBa;
}
- /** @deprecated unused */
+ /** @deprecated unused, does not call native */
@Override
public double doubleValue() {
- if (_nativeOk)
- return nativeDoubleValue(toByteArray());
- else
return super.doubleValue();
}
/**
@@ -281,7 +269,7 @@ public class NativeBigInteger extends BigInteger {
}
/**
- * <p>Compare the BigInteger.modPow/doubleValue vs the NativeBigInteger.modPow/doubleValue of some
+ * <p>Compare the BigInteger.modPow vs the NativeBigInteger.modPow of some
* really big (2Kbit) numbers 100 different times and benchmark the
* performance (or shit a brick if they don't match). </p>
*
@@ -289,8 +277,6 @@ public class NativeBigInteger extends BigInteger {
public static void main(String args[]) {
_doLog = true;
runModPowTest(100);
- // i2p doesn't care about the double values
- //runDoubleValueTest(100);
}
/* the sample numbers are elG generator/prime so we can test with reasonable numbers */
@@ -361,64 +347,6 @@ public class NativeBigInteger extends BigInteger {
}
}
-/********
- private static void runDoubleValueTest(int numRuns) {
- System.out.println("DEBUG: Warming up the random number generator...");
- SecureRandom rand = new SecureRandom();
- rand.nextBoolean();
- System.out.println("DEBUG: Random number generator warmed up");
-
- BigInteger jg = new BigInteger(_sampleGenerator);
-
- long totalTime = 0;
- long javaTime = 0;
-
- int MULTIPLICATOR = 50000; //Run the doubleValue() calls within a loop since they are pretty fast..
- int runsProcessed = 0;
- for (runsProcessed = 0; runsProcessed < numRuns; runsProcessed++) {
- NativeBigInteger g = new NativeBigInteger(_sampleGenerator);
- long beforeDoubleValue = System.currentTimeMillis();
- double dNative=0;
- for(int mult=0;mult<MULTIPLICATOR;mult++)
- dNative = g.doubleValue();
- long afterDoubleValue = System.currentTimeMillis();
- double jval=0;
- for(int mult=0;mult<MULTIPLICATOR;mult++)
- jval = jg.doubleValue();
- long afterJavaDoubleValue = System.currentTimeMillis();
-
- totalTime += (afterDoubleValue - beforeDoubleValue);
- javaTime += (afterJavaDoubleValue - afterDoubleValue);
- if (dNative!=jval) {
- System.err.println("ERROR: [" + runsProcessed + "]\tnative double != java double");
- System.err.println("ERROR: native double value: " + dNative);
- System.err.println("ERROR: java double value: " + jval);
- System.err.println("ERROR: run time: " + totalTime + "ms (" + (totalTime / (runsProcessed + 1)) + "ms each)");
- break;
- } else {
- System.out.println("DEBUG: current run time: " + (afterDoubleValue - beforeDoubleValue) + "ms (total: "
- + totalTime + "ms, " + (totalTime / (runsProcessed + 1)) + "ms each)");
- }
- }
- System.out.println("INFO: run time: " + totalTime + "ms (" + (totalTime / (runsProcessed + 1)) + "ms each)");
- if (numRuns == runsProcessed)
- System.out.println("INFO: " + runsProcessed + " runs complete without any errors");
- else
- System.out.println("ERROR: " + runsProcessed + " runs until we got an error");
-
- if (_nativeOk) {
- System.out.println("native run time: \t" + totalTime + "ms (" + (totalTime / (runsProcessed + 1))
- + "ms each)");
- System.out.println("java run time: \t" + javaTime + "ms (" + (javaTime / (runsProcessed + 1)) + "ms each)");
- System.out.println("native = " + ((totalTime * 100.0d) / (double) javaTime) + "% of pure java time");
- } else {
- System.out.println("java run time: \t" + javaTime + "ms (" + (javaTime / (runsProcessed + 1)) + "ms each)");
- System.out.println("However, we couldn't load the native library, so this doesn't test much");
- }
- }
-*********/
-
-
/**
* <p>Do whatever we can to load up the native library backing this BigInteger's native methods.
* If it can find a custom built jbigi.dll / libjbigi.so, it'll use that. Otherwise
--
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