Implement infrastracture for mocking up QEMU capabilities cache

The main purpose of this patch is to introduce test mode to
virQEMUCapsCacheLookup(). This is done by adding a global variable, which
effectively overrides binary name. This variable is supposed to be set by
test suite.

The second addition is qemuTestCapsCacheInsert() function which allows the
test suite to actually populate the cache.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>

src/qemu/qemu_capabilities.c

@@ -42,6 +42,8 @@
 #include "virstring.h"
 #include "qemu_hostdev.h"
 #include "qemu_domain.h"
+#define __QEMU_CAPSRIV_H_ALLOW__
+#include "qemu_capspriv.h"
 
 #include <fcntl.h>
 #include <sys/stat.h>
@@ -331,15 +333,6 @@ struct _virQEMUCaps {
     unsigned int *machineMaxCpus;
 };
 
-struct _virQEMUCapsCache {
-    virMutex lock;
-    virHashTablePtr binaries;
-    char *libDir;
-    char *cacheDir;
-    uid_t runUid;
-    gid_t runGid;
-};
-
 struct virQEMUCapsSearchData {
     virArch arch;
 };
@@ -3744,11 +3737,17 @@ virQEMUCapsCacheNew(const char *libDir,
     return NULL;
 }
 
+const char *qemuTestCapsName;
 
 virQEMUCapsPtr
 virQEMUCapsCacheLookup(virQEMUCapsCachePtr cache, const char *binary)
 {
     virQEMUCapsPtr ret = NULL;
+
+    /* This is used only by test suite!!! */
+    if (qemuTestCapsName)
+        binary = qemuTestCapsName;
+
     virMutexLock(&cache->lock);
     ret = virHashLookup(cache->binaries, binary);
     if (ret &&

src/qemu/qemu_capspriv.h

@@ -0,0 +1,40 @@
+/*
+ * qemu_capspriv.h: private declarations for QEMU capabilities generation
+ *
+ * Copyright (C) 2015 Samsung Electronics Co. Ltd
+ * Copyright (C) 2015 Pavel Fedin
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Author: Pavel Fedin <p.fedin@samsung.com>
+ */
+
+#ifndef __QEMU_CAPSRIV_H_ALLOW__
+# error "qemu_capspriv.h may only be included by qemu_capabilities.c or test suites"
+#endif
+
+#ifndef __QEMU_CAPSPRIV_H__
+# define __QEMU_CAPSPRIV_H__
+
+struct _virQEMUCapsCache {
+    virMutex lock;
+    virHashTablePtr binaries;
+    char *libDir;
+    char *cacheDir;
+    uid_t runUid;
+    gid_t runGid;
+};
+
+#endif

tests/testutilsqemu.c

@@ -8,6 +8,8 @@
 # include "cpu_conf.h"
 # include "qemu/qemu_driver.h"
 # include "qemu/qemu_domain.h"
+# define __QEMU_CAPSRIV_H_ALLOW__
+# include "qemu/qemu_capspriv.h"
 # include "virstring.h"
 
 # define VIR_FROM_THIS VIR_FROM_QEMU
@@ -529,11 +531,38 @@ qemuTestParseCapabilities(const char *capsFile)
 
 void qemuTestDriverFree(virQEMUDriver *driver)
 {
+    virQEMUCapsCacheFree(driver->qemuCapsCache);
     virObjectUnref(driver->xmlopt);
     virObjectUnref(driver->caps);
     virObjectUnref(driver->config);
 }
 
+int qemuTestCapsCacheInsert(virQEMUCapsCachePtr cache, const char *binary,
+                            virQEMUCapsPtr caps)
+{
+    int ret;
+
+    if (caps) {
+        /* Our caps were created artificially, so we don't want
+         * virQEMUCapsCacheFree() to attempt to deallocate them */
+        virObjectRef(caps);
+    } else {
+        caps = virQEMUCapsNew();
+        if (!caps)
+            return -ENOMEM;
+    }
+
+    /* We can have repeating names for our test data sets,
+     * so make sure there's no old copy */
+    virHashRemoveEntry(cache->binaries, binary);
+
+    ret = virHashAddEntry(cache->binaries, binary, caps);
+    if (ret < 0)
+        virObjectUnref(caps);
+
+    return ret;
+}
+
 int qemuTestDriverInit(virQEMUDriver *driver)
 {
     driver->config = virQEMUDriverConfigNew(false);
@@ -554,4 +583,5 @@ int qemuTestDriverInit(virQEMUDriver *driver)
     qemuTestDriverFree(driver);
     return -1;
 }
+
 #endif

tests/testutilsqemu.h

@@ -18,4 +18,9 @@ void testQemuCapsSetCPU(virCapsPtr caps,
 
 int qemuTestDriverInit(virQEMUDriver *driver);
 void qemuTestDriverFree(virQEMUDriver *driver);
+int qemuTestCapsCacheInsert(virQEMUCapsCachePtr cache, const char *binary,
+                            virQEMUCapsPtr caps);
+
+/* This variable is actually defined in src/qemu/qemu_capabilities.c */
+extern const char *qemuTestCapsName;
 #endif