* TODO: updated, and added python hooks for error handling

* include/virterror.h src/virterror.c src/xml.c: error interception
  and reporting should be done.
Daniel

ChangeLog

@@ -1,3 +1,9 @@
+Mon Feb 27 17:33:16 EST 2006 Daniel Veillard <veillard@redhat.com>
+
+	* TODO: updated, and added python hooks for error handling
+	* include/virterror.h src/virterror.c src/xml.c: error interception
+	  and reporting should be done.
+
 Mon Feb 27 16:42:46 EST 2006 Daniel Veillard <veillard@redhat.com>
 
 	* src/libvirt.c src/xen_internal.[ch]: virConnectOpenReadOnly()

TODO

@@ -1,7 +1,5 @@
 Absolute TODOs:
 - thread protection, reentrancy, refcounting, etc ...
-- Error API. probably similar to libxml2 structured API
-- extract error messages from the Xend rpc
 
 TODO:
 - Create() API, how do we best keep flexibility and allow various
@@ -13,6 +11,7 @@ TODO:
 - in python bindings raise an exception if a lookup or connection fails
   to return a non-None object
 - Add uuid to XML format
+- add error handling hooks at the python level
 
 virsh TODO:
 - decide where will be default directory for domains configurations (/etc/xen/domains/* ?)
@@ -46,3 +45,5 @@ Done:
 - the CreateLinux() API is a first step toward a final Create()
 - documentation and examples on using the toolkit
 - UUID based lookup and naming
+- Error API similar to libxml2 structured API
+- extract error messages from the Xend rpc

include/libvirt/virterror.h

@@ -41,6 +41,7 @@ typedef enum {
     VIR_FROM_XEN,	/* Error at Xen hypervisor layer */
     VIR_FROM_XEND,	/* Error at connection with xend daemon */
     VIR_FROM_SEXPR,	/* Error in the S-Epression code */
+    VIR_FROM_XML,	/* Error in the XML code */
     VIR_FROM_DOM,	/* Error when operating on a domain */
 } virErrorDomain;
 
@@ -89,6 +90,14 @@ typedef enum {
     VIR_ERR_SEXPR_SERIAL,/* failure to serialize an S-Expr */
     VIR_ERR_NO_XEN,/* could not open Xen hypervisor control */
     VIR_ERR_XEN_CALL,/* failure doing an hypervisor call */
+    VIR_ERR_OS_TYPE, /* unknown OS type */
+    VIR_ERR_NO_KERNEL, /* missing kernel informations */
+    VIR_ERR_NO_ROOT, /* missing root device informations */
+    VIR_ERR_NO_SOURCE, /* missing source device informations */
+    VIR_ERR_NO_TARGET, /* missing target device informations */
+    VIR_ERR_NO_NAME, /* missing domain name informations */
+    VIR_ERR_NO_OS, /* missing domain OS informations */
+    VIR_ERR_NO_DEVICE, /* missing domain devices informations */
 } virErrorNumber;
 
 /**

include/virterror.h

@@ -41,6 +41,7 @@ typedef enum {
     VIR_FROM_XEN,	/* Error at Xen hypervisor layer */
     VIR_FROM_XEND,	/* Error at connection with xend daemon */
     VIR_FROM_SEXPR,	/* Error in the S-Epression code */
+    VIR_FROM_XML,	/* Error in the XML code */
     VIR_FROM_DOM,	/* Error when operating on a domain */
 } virErrorDomain;
 
@@ -89,6 +90,14 @@ typedef enum {
     VIR_ERR_SEXPR_SERIAL,/* failure to serialize an S-Expr */
     VIR_ERR_NO_XEN,/* could not open Xen hypervisor control */
     VIR_ERR_XEN_CALL,/* failure doing an hypervisor call */
+    VIR_ERR_OS_TYPE, /* unknown OS type */
+    VIR_ERR_NO_KERNEL, /* missing kernel informations */
+    VIR_ERR_NO_ROOT, /* missing root device informations */
+    VIR_ERR_NO_SOURCE, /* missing source device informations */
+    VIR_ERR_NO_TARGET, /* missing target device informations */
+    VIR_ERR_NO_NAME, /* missing domain name informations */
+    VIR_ERR_NO_OS, /* missing domain OS informations */
+    VIR_ERR_NO_DEVICE, /* missing domain devices informations */
 } virErrorNumber;
 
 /**

src/virterror.c

@@ -424,6 +424,51 @@ __virErrorMsg(virErrorNumber error, const char *info) {
 	case VIR_ERR_XEN_CALL:
 	    errmsg = "failed Xen syscall %s %d";
 	    break;
+	case VIR_ERR_OS_TYPE:
+	    if (info == NULL)
+	        errmsg = "unknown OS type";
+	    else
+	        errmsg = "unknown OS type %s";
+	    break;
+	case VIR_ERR_NO_KERNEL:
+	    errmsg = "missing kernel informations";
+	    break;
+	case VIR_ERR_NO_ROOT:
+	    if (info == NULL)
+		errmsg = "missing root device informations";
+	    else
+		errmsg = "missing root device informations in %s";
+	    break;
+	case VIR_ERR_NO_SOURCE:
+	    if (info == NULL)
+		errmsg = "missing source informations for device";
+	    else
+		errmsg = "missing source informations for device %s";
+	    break;
+	case VIR_ERR_NO_TARGET:
+	    if (info == NULL)
+		errmsg = "missing target informations for device";
+	    else
+		errmsg = "missing target informations for device %s";
+	    break;
+	case VIR_ERR_NO_NAME:
+	    if (info == NULL)
+		errmsg = "missing domain name informations";
+	    else
+		errmsg = "missing domain name informations in %s";
+	    break;
+	case VIR_ERR_NO_OS:
+	    if (info == NULL)
+		errmsg = "missing operating system informations";
+	    else
+		errmsg = "missing operating system informations for %s";
+	    break;
+	case VIR_ERR_NO_DEVICE:
+	    if (info == NULL)
+		errmsg = "missing devices informations";
+	    else
+		errmsg = "missing devices informations for %s";
+	    break;
     }
     return(errmsg);
 }

src/xml.c

@@ -23,6 +23,27 @@
 #include "sexpr.h"
 #include "xml.h"
 
+/**
+ * virXenError:
+ * @conn: the connection if available
+ * @error: the error number
+ * @info: extra information string
+ *
+ * Handle an error at the xend daemon interface
+ */
+static void
+virXMLError(virErrorNumber error, const char *info, int value) {
+    const char *errmsg;
+    
+    if (error == VIR_ERR_OK)
+        return;
+
+    errmsg = __virErrorMsg(error, info);
+    __virRaiseError(NULL, NULL, VIR_FROM_XML, error, VIR_ERR_ERROR,
+                    errmsg, info, NULL, value, 0, errmsg, info,
+		    value);
+}
+
 /**
  * virBufferGrow:
  * @buf:  the buffer
@@ -44,6 +65,7 @@ virBufferGrow(virBufferPtr buf, unsigned int len) {
 
     newbuf = (char *) realloc(buf->content, size);
     if (newbuf == NULL) {
+        virXMLError(VIR_ERR_NO_MEMORY, "growing buffer", size);
         return(-1);
     }
     buf->content = newbuf;
@@ -514,11 +536,12 @@ virDomainParseXMLOSDesc(xmlNodePtr node, virBufferPtr buf) {
     }
     if ((type != NULL) && (!xmlStrEqual(type, BAD_CAST "linux"))) {
         /* VIR_ERR_OS_TYPE */
+	virXMLError(VIR_ERR_OS_TYPE, (const char *) type, 0);
 	return(-1);
     }
     virBufferAdd(buf, "(linux ", 7);
     if (kernel == NULL) {
-        /* VIR_ERR_NO_KERNEL */
+	virXMLError(VIR_ERR_NO_KERNEL, NULL, 0);
 	return(-1);
     }
     virBufferVSprintf(buf, "(kernel '%s')", (const char *) kernel);
@@ -528,7 +551,7 @@ virDomainParseXMLOSDesc(xmlNodePtr node, virBufferPtr buf) {
 	const xmlChar *base, *tmp;
         /* need to extract root info from command line */
 	if (cmdline == NULL) {
-	    /* VIR_ERR_NO_ROOT */
+	    virXMLError(VIR_ERR_NO_ROOT, (const char *) cmdline, 0);
 	    return(-1);
 	}
 	base = cmdline;
@@ -548,7 +571,7 @@ virDomainParseXMLOSDesc(xmlNodePtr node, virBufferPtr buf) {
 	tmp = base;
 	while ((*tmp != 0) && (*tmp != ' ') && (*tmp != '\t')) tmp++;
 	if (tmp == base) {
-	    /* VIR_ERR_NO_ROOT */
+	    virXMLError(VIR_ERR_NO_ROOT, (const char *) cmdline, 0);
 	    return(-1);
 	}
 	root = xmlStrndup(base, tmp - base);
@@ -612,13 +635,14 @@ virDomainParseXMLDiskDesc(xmlNodePtr node, virBufferPtr buf) {
     }
 
     if (source == NULL) {
-        /* VIR_ERR_NO_SOURCE */
+	virXMLError(VIR_ERR_NO_SOURCE, (const char *) target, 0);
+	
 	if (target != NULL)
 	    xmlFree(target);
 	return(-1);
     }
     if (target == NULL) {
-        /* VIR_ERR_NO_TARGET */
+	virXMLError(VIR_ERR_NO_TARGET, (const char *) source, 0);
 	if (source != NULL)
 	    xmlFree(source);
 	return(-1);
@@ -733,7 +757,7 @@ char *
 virDomainParseXMLDesc(const char *xmldesc, char **name) {
     xmlDocPtr xml = NULL;
     xmlNodePtr node;
-    char *ret = NULL;
+    char *ret = NULL, *nam = NULL;
     virBuffer buf;
     xmlChar *prop;
     xmlXPathObjectPtr obj = NULL;
@@ -778,12 +802,15 @@ virDomainParseXMLDesc(const char *xmldesc, char **name) {
     obj = xmlXPathEval(BAD_CAST "string(/domain/name[1])", ctxt);
     if ((obj == NULL) || (obj->type != XPATH_STRING) || 
         (obj->stringval == NULL) || (obj->stringval[0] == 0)) {
-	/* VIR_ERR_NO_NAME */
+	virXMLError(VIR_ERR_NO_NAME, xmldesc, 0);
         goto error;
     }
     virBufferVSprintf(&buf, "(name '%s')", obj->stringval);
-    if (name != NULL)
-	*name = strdup((const char *) obj->stringval);
+    nam = strdup((const char *) obj->stringval);
+    if (nam == NULL) {
+	virXMLError(VIR_ERR_NO_MEMORY, "copying name", 0);
+	goto error;
+    }
     xmlXPathFreeObject(obj);
 
     obj = xmlXPathEval(BAD_CAST "number(/domain/memory[1])", ctxt);
@@ -812,7 +839,7 @@ virDomainParseXMLDesc(const char *xmldesc, char **name) {
     if ((obj == NULL) || (obj->type != XPATH_NODESET) ||
         (obj->nodesetval == NULL) ||
 	(obj->nodesetval->nodeNr != 1)) {
-	/* VIR_ERR_NO_OS */
+	virXMLError(VIR_ERR_NO_OS, nam, 0);
         goto error;
     }
     res = virDomainParseXMLOSDesc(obj->nodesetval->nodeTab[0], &buf);
@@ -827,7 +854,7 @@ virDomainParseXMLDesc(const char *xmldesc, char **name) {
     if ((obj == NULL) || (obj->type != XPATH_NODESET) ||
         (obj->nodesetval == NULL) ||
 	(obj->nodesetval->nodeNr < 1)) {
-	/* VIR_ERR_NO_DEVICE */
+	virXMLError(VIR_ERR_NO_DEVICE, nam, 0);
         goto error;
     }
     for (i = 0;i < obj->nodesetval->nodeNr;i++) {
@@ -859,15 +886,17 @@ virDomainParseXMLDesc(const char *xmldesc, char **name) {
 
     xmlXPathFreeContext(ctxt);
     xmlFreeDoc(xml);
+
+    if (name != NULL)
+	*name = nam;
     
     return(ret);
 
 error:
-    if (name != NULL) {
-        if (*name != NULL)
-	    free(*name);
+    if (nam != NULL)
+	free(nam);
+    if (name != NULL)
 	*name = NULL;
-    }
     if (obj != NULL)
         xmlXPathFreeObject(obj);
     if (ctxt != NULL)