[libvirt] [PATCH 2/4] Implement infrastracture for mocking up QEMU capabilities cache

[Ján Tomko]

From: Pavel Fedin <p.fedin at samsung.com>

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 at samsung.com>
Signed-off-by: Ján Tomko <jtomko at redhat.com>
---
 src/qemu/qemu_capabilities.c | 16 +++++++---------
 src/qemu/qemu_capspriv.h     | 36 ++++++++++++++++++++++++++++++++++++
 tests/testutilsqemu.c        | 40 ++++++++++++++++++++++++++++++++++++++++
 tests/testutilsqemu.h        |  5 +++++
 4 files changed, 88 insertions(+), 9 deletions(-)
 create mode 100644 src/qemu/qemu_capspriv.h

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 4ad1bdb..9a819d2 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -42,6 +42,7 @@
 #include "virstring.h"
 #include "qemu_hostdev.h"
 #include "qemu_domain.h"
+#include "qemu_capspriv.h"
 
 #include <fcntl.h>
 #include <sys/stat.h>
@@ -331,15 +332,6 @@ 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;
 };
@@ -3718,11 +3710,17 @@ 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 &&
diff --git a/src/qemu/qemu_capspriv.h b/src/qemu/qemu_capspriv.h
new file mode 100644
index 0000000..9288dbd
--- /dev/null
+++ b/src/qemu/qemu_capspriv.h
@@ -0,0 +1,36 @@
+/*
+ * 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 at samsung.com>
+ */
+
+#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
diff --git a/tests/testutilsqemu.c b/tests/testutilsqemu.c
index 84dfa75..275d22a 100644
--- a/tests/testutilsqemu.c
+++ b/tests/testutilsqemu.c
@@ -8,6 +8,7 @@
 # include "cpu_conf.h"
 # include "qemu/qemu_driver.h"
 # include "qemu/qemu_domain.h"
+# include "qemu/qemu_capspriv.h"
 # include "virstring.h"
 
 # define VIR_FROM_THIS VIR_FROM_QEMU
@@ -527,6 +528,32 @@ qemuTestParseCapabilities(const char *capsFile)
     return NULL;
 }
 
+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);
@@ -537,13 +564,24 @@ int qemuTestDriverInit(virQEMUDriver *driver)
     if (!driver->caps)
         goto error;
 
+    /* Using /dev/null for libDir and cacheDir automatically produces errors
+     * upon attempt to use any of them */
+    driver->qemuCapsCache = virQEMUCapsCacheNew("/dev/null", "/dev/null", 0, 0);
+    if (!driver->qemuCapsCache)
+        goto error;
+
     driver->xmlopt = virQEMUDriverCreateXMLConf(driver);
     if (!driver->xmlopt)
         goto error;
 
+    qemuTestCapsName = "empty";
+    if (qemuTestCapsCacheInsert(driver->qemuCapsCache, "empty", NULL) < 0)
+        goto error;
+
     return 0;
 
  error:
+    virQEMUCapsCacheFree(driver->qemuCapsCache);
     virObjectUnref(driver->caps);
     virObjectUnref(driver->config);
     virObjectUnref(driver->xmlopt);
@@ -552,8 +590,10 @@ int qemuTestDriverInit(virQEMUDriver *driver)
 
 void qemuTestDriverFree(virQEMUDriver *driver)
 {
+    virQEMUCapsCacheFree(driver->qemuCapsCache);
     virObjectUnref(driver->xmlopt);
     virObjectUnref(driver->caps);
     virObjectUnref(driver->config);
 }
+
 #endif
diff --git a/tests/testutilsqemu.h b/tests/testutilsqemu.h
index 6c2d3b5..1d5dfc5 100644
--- a/tests/testutilsqemu.h
+++ b/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
-- 
2.4.6