[libvirt] [java] [PATCH] GetNodeCpuStat binding

From: Pasquale Di Rienzo <phate867(a)gmail.com&gt; -Added the getNodeCpuStat binding to Libvirt class -Added virNodeCPUStats and CPUStat classes to support this binding -Added the method getCPUStats to Connect class --- AUTHORS | 1 + src/main/java/org/libvirt/CPUStat.java | 57 ++++++++++++++++++++++ src/main/java/org/libvirt/Connect.java | 53 ++++++++++++++++++++ src/main/java/org/libvirt/jna/Libvirt.java | 5 ++ src/main/java/org/libvirt/jna/virNodeCPUStats.java | 19 ++++++++ 5 files changed, 135 insertions(+) create mode 100644 src/main/java/org/libvirt/CPUStat.java create mode 100644 src/main/java/org/libvirt/jna/virNodeCPUStats.java diff --git a/AUTHORS b/AUTHORS index 07809bf..77139e5 100644 --- a/AUTHORS +++ b/AUTHORS @@ -16,3 +16,4 @@ Andrea Sansottera <andrea.sansottera(a)gmail.com&gt; Stefan Majer <stefan.majer(a)gmail.com&gt; Wido den Hollander <wido(a)widodh.nl&gt; Eric Blake <eblake(a)redhat.com&gt; +Pasquale Di Rienzo <phate867(a)gmail.com&gt; diff --git a/src/main/java/org/libvirt/CPUStat.java b/src/main/java/org/libvirt/CPUStat.java new file mode 100644 index 0000000..527049c --- /dev/null +++ b/src/main/java/org/libvirt/CPUStat.java @@ -0,0 +1,57 @@ +package org.libvirt; + +import java.nio.charset.Charset; +import org.libvirt.jna.virNodeCPUStats; +import org.libvirt.jna.virTypedParameter; + +/** + * This class holds a cpu time. + * The tag attribute is a string of either "kernel","user","idle","iowait" + * while the value attribute is the actual time value + * @author Pasquale Di Rienzo + * + */ +public class CPUStat { + public String tag; + public long value; + + private String createStringFromBytes(byte[] b){ + Charset ch = Charset.forName("UTF-8"); + int i = 0; + while ((i<b.length) && (b[i]!=0)) + i++; + + return new String(b,0,i,ch); + } + + public CPUStat(virNodeCPUStats stat){ + tag = createStringFromBytes(stat.field); + value = stat.value.longValue(); + } + + public CPUStat(virTypedParameter stat){ + tag = createStringFromBytes(stat.field); + value = stat.value.l; + } + + public String getTag() { + return tag; + } + + public long getValue() { + return value; + } + + public void setTag(String tag) { + this.tag = tag; + } + + public void setValue(long val) { + this.value = val; + } + + @Override + public String toString() { + return String.format("tag:%s%nval:%d%n", tag, value); + } +} diff --git a/src/main/java/org/libvirt/Connect.java b/src/main/java/org/libvirt/Connect.java index fedc60e..d8a4ce2 100644 --- a/src/main/java/org/libvirt/Connect.java +++ b/src/main/java/org/libvirt/Connect.java @@ -2,6 +2,8 @@ package org.libvirt; import java.util.UUID; +import org.libvirt.CPUStat; +import org.libvirt.LibvirtException; import org.libvirt.jna.ConnectionPointer; import org.libvirt.jna.DevicePointer; import org.libvirt.jna.DomainPointer; @@ -14,6 +16,7 @@ import org.libvirt.jna.StoragePoolPointer; import org.libvirt.jna.StorageVolPointer; import org.libvirt.jna.StreamPointer; import org.libvirt.jna.virConnectAuth; +import org.libvirt.jna.virNodeCPUStats; import org.libvirt.jna.virNodeInfo; import static org.libvirt.Library.libvirt; @@ -23,6 +26,7 @@ import static org.libvirt.ErrorHandler.processErrorIfZero; import com.sun.jna.Memory; import com.sun.jna.NativeLong; import com.sun.jna.Pointer; +import com.sun.jna.ptr.IntByReference; import com.sun.jna.ptr.LongByReference; /** @@ -207,6 +211,55 @@ public class Connect { } return processError(success); } + + /** + * This function returns statistics about the cpu, that is the time + * each cpu is spending in kernel time, user time, io time and idle time. + * Each CPUStat object refers to a particular time. + * + * Note that not all these stats are granted to be retrieved. + * + * @param the number of the cpu you want to retrieve stats from. + * passing -1 will make this function retrieve a mean value + * from all cpus the system has. + * + * @param some flags + * @return a cpustat object for each cpu + * @throws LibvirtException + */ + public CPUStat[] getCPUStats(int cpuNumber,long flags) throws LibvirtException{ + CPUStat[] stats = null; + + IntByReference nParams = new IntByReference(); + + //according to libvirt reference you call this function once passing + //null as param paramether to get the actual stats (kernel,user,io,idle) number into the + //nParams reference. Generally this number would be 4, but some systems + //may not give all 4 times, so it is always good to call it. + int result = libvirt.virNodeGetCPUStats( + VCP, cpuNumber, null, nParams, flags); + + processError(result); + + if(result == 0){//dunno if this check is actually needed + + //this time we create an array to fit the number of paramethers + virNodeCPUStats[] params = new virNodeCPUStats[nParams.getValue()]; + //and we pass it to the function + result = libvirt.virNodeGetCPUStats(VCP, cpuNumber , params, nParams, flags); + processError(result); + + //finally we parse the result in an user friendly class which does + //not expose libvirt's internal paramethers + if(result >= 0){ + stats = new CPUStat[params.length]; + for(int i=0;i<params.length;i++) + stats[i] = new CPUStat(params[i]); + } + } + + return stats; + } /** * Compares the given CPU description with the host CPU diff --git a/src/main/java/org/libvirt/jna/Libvirt.java b/src/main/java/org/libvirt/jna/Libvirt.java index 0e4c9fc..658299f 100644 --- a/src/main/java/org/libvirt/jna/Libvirt.java +++ b/src/main/java/org/libvirt/jna/Libvirt.java @@ -1,5 +1,8 @@ package org.libvirt.jna; +import org.libvirt.jna.ConnectionPointer; +import org.libvirt.jna.virNodeCPUStats; + import com.sun.jna.Callback; import com.sun.jna.Library; import com.sun.jna.Native; @@ -267,6 +270,8 @@ public interface Libvirt extends Library { int virNetworkUndefine(NetworkPointer virConnectPtr); // Node functions + int virNodeGetCPUStats(ConnectionPointer virConnectPtr, int cpuNum, + virNodeCPUStats[] stats,IntByReference nparams, long flags); int virNodeGetInfo(ConnectionPointer virConnectPtr, virNodeInfo virNodeInfo); int virNodeGetCellsFreeMemory(ConnectionPointer virConnectPtr, LongByReference freeMems, int startCell, int maxCells); diff --git a/src/main/java/org/libvirt/jna/virNodeCPUStats.java b/src/main/java/org/libvirt/jna/virNodeCPUStats.java new file mode 100644 index 0000000..a8f2dca --- /dev/null +++ b/src/main/java/org/libvirt/jna/virNodeCPUStats.java @@ -0,0 +1,19 @@ +package org.libvirt.jna; + +import java.util.Arrays; +import java.util.List; + +import com.sun.jna.NativeLong; +import com.sun.jna.Structure; + +public class virNodeCPUStats extends Structure{ + public byte[] field = new byte[80]; + public NativeLong value ; + + private static final List fields = Arrays.asList( "field", "value"); + + @Override + protected List getFieldOrder() { + return fields; + } +} -- 1.8.3.2