[libvirt] [PATCH libvirt-java 1/2] Return a byte[] array with secretGetValue
Daniel Veillard
veillard at redhat.com
Thu Jul 5 08:20:08 UTC 2012
On Tue, Jun 26, 2012 at 10:07:31AM +0200, Wido den Hollander wrote:
> We break the API with this, but Java does not support multiple method signatures with different return types.
>
> The old method returned a String, but since a secret can be binary data this type is not suited.
>
> Users who now that their secret is in fact a String, can use cast with:
>
> Secret secret = conn.secretLookupByUUIDString("uuuuuuuid");
> String value = new String(secret.getValue());
While it makes perfect sense to switch the jna layer to byte array as
otherwise we can't guarantee functional operation in all cases, I aslo
think we should not break compatibility, since Java doesn't allow
overload with different value type, it just mean we need a new method
name.
So I'm simply renaming your method name to "getByteValue" but keeping
getValue() implemented with the cast you suggest, that seems to work for
me
> Signed-off-by: Wido den Hollander <wido at widodh.nl>
> ---
> src/main/java/org/libvirt/Secret.java | 13 ++++++++++---
> src/main/java/org/libvirt/jna/Libvirt.java | 2 +-
> 2 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/src/main/java/org/libvirt/Secret.java b/src/main/java/org/libvirt/Secret.java
> index 48f7895..39d9122 100644
> --- a/src/main/java/org/libvirt/Secret.java
> +++ b/src/main/java/org/libvirt/Secret.java
> @@ -5,6 +5,9 @@ import org.libvirt.jna.SecretPointer;
>
> import com.sun.jna.Native;
> import com.sun.jna.NativeLong;
> +import com.sun.jna.ptr.LongByReference;
> +import com.sun.jna.Pointer;
> +import java.nio.ByteBuffer;
>
> /**
> * A secret defined by libvirt
> @@ -106,12 +109,16 @@ public class Secret {
>
> /**
> * Fetches the value of the secret
> - *
> + *
> * @return the value of the secret, or null on failure.
> */
> - public String getValue() throws LibvirtException {
> - String returnValue = libvirt.virSecretGetValue(VSP, new NativeLong(), 0);
> + public byte[] getValue() throws LibvirtException {
> + LongByReference value_size = new LongByReference();
> + Pointer value = libvirt.virSecretGetValue(VSP, value_size, 0);
> processError();
> + ByteBuffer bb = value.getByteBuffer(0, value_size.getValue());
> + byte[] returnValue = new byte[bb.remaining()];
> + bb.get(returnValue);
> return returnValue;
> }
>
> diff --git a/src/main/java/org/libvirt/jna/Libvirt.java b/src/main/java/org/libvirt/jna/Libvirt.java
> index b1e53a2..f53199d 100644
> --- a/src/main/java/org/libvirt/jna/Libvirt.java
> +++ b/src/main/java/org/libvirt/jna/Libvirt.java
> @@ -330,7 +330,7 @@ public interface Libvirt extends Library {
> public int virSecretGetUUID(SecretPointer virSecretPtr, byte[] uuidString);
> public int virSecretGetUUIDString(SecretPointer virSecretPtr, byte[] uuidString);
> public String virSecretGetUsageID(SecretPointer virSecretPtr);
> - public String virSecretGetValue(SecretPointer virSecretPtr, NativeLong value_size, int flags);
> + public Pointer virSecretGetValue(SecretPointer virSecretPtr, LongByReference value_size, int flags);
> public String virSecretGetXMLDesc(SecretPointer virSecretPtr, int flags);
> public SecretPointer virSecretLookupByUsage(ConnectionPointer virConnectPtr, int usageType, String usageID);
> public SecretPointer virSecretLookupByUUID(ConnectionPointer virConnectPtr, byte[] uuidBytes);
> --
> 1.7.9.5
So I'm squashing the following on top of your patch.
I will reword the commit message slightly too. I'm sorry that this mean
you will have to rename getValue() to getByteValue() but I prefer that
than risking to break an unknown amount of existing users ... I hope you
understand.
diff --git a/src/main/java/org/libvirt/Secret.java b/src/main/java/org/libvirt/Secret.java
index 39d9122..561c258 100644
--- a/src/main/java/org/libvirt/Secret.java
+++ b/src/main/java/org/libvirt/Secret.java
@@ -108,11 +108,23 @@ public class Secret {
}
/**
- * Fetches the value of the secret
+ * Fetches the value of the secret as a string (note that
+ * this may not always work and getByteValue() is more reliable)
+ * This is just kept for backward compatibility
*
* @return the value of the secret, or null on failure.
*/
- public byte[] getValue() throws LibvirtException {
+ public String getValue() throws LibvirtException {
+ String returnValue = new String(getByteValue());
+ return returnValue;
+ }
+
+ /**
+ * Fetches the value of the secret as a byte array
+ *
+ * @return the value of the secret, or null on failure.
+ */
+ public byte[] getByteValue() throws LibvirtException {
LongByReference value_size = new LongByReference();
Pointer value = libvirt.virSecretGetValue(VSP, value_size, 0);
processError();
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel at veillard.com | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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