[Qemu-devel] [PATCH V2 3/6] libqblock error handling

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

  This patch contains error handling APIs, which user could call them to
get error details.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
---
 libqblock/libqblock-error.c |   60 +++++++++++++++++++++++++++++++++++++++++++
 libqblock/libqblock-error.h |   50 +++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+), 0 deletions(-)
 create mode 100644 libqblock/libqblock-error.c
 create mode 100644 libqblock/libqblock-error.h

diff --git a/libqblock/libqblock-error.c b/libqblock/libqblock-error.c
new file mode 100644
index 0000000..d5ebabf
--- /dev/null
+++ b/libqblock/libqblock-error.c
@@ -0,0 +1,60 @@
+/*
+ * QEMU block layer library
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Wenchao Xia   <xiawenc@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "libqblock-error.h"
+#include "libqblock-internal.h"
+
+void qb_error_get_human_str(struct QBroker *broker,
+                            char *buf, int buf_size)
+{
+    const char *err_ret_str;
+    switch (broker->err_ret) {
+    case QB_ERR_MEM_ERR:
+        err_ret_str = "Not enough memory.";
+        break;
+    case QB_ERR_INTERNAL_ERR:
+        err_ret_str = "Internal error.";
+        break;
+    case QB_ERR_INVALID_PARAM:
+        err_ret_str = "Invalid param.";
+        break;
+    case QB_ERR_BLOCK_OUT_OF_RANGE:
+        err_ret_str = "request is out of image's range.";
+        break;
+    default:
+        err_ret_str = "Unknow error.";
+        break;
+    }
+    if (broker == NULL) {
+        snprintf(buf, buf_size, "%s", err_ret_str);
+        return;
+    }
+
+    if (broker->err_ret == QB_ERR_INTERNAL_ERR) {
+        snprintf(buf, buf_size, "%s %s errno [%d]. strerror [%s].",
+                     err_ret_str, broker->err_msg,
+                     broker->err_no, strerror(-broker->err_no));
+    } else {
+        snprintf(buf, buf_size, "%s %s",
+                     err_ret_str, broker->err_msg);
+    }
+    return;
+}
+
+int qb_error_get_errno(struct QBroker *broker)
+{
+    if (broker->err_ret == QB_ERR_INTERNAL_ERR) {
+        return broker->err_no;
+    }
+    return 0;
+}
diff --git a/libqblock/libqblock-error.h b/libqblock/libqblock-error.h
new file mode 100644
index 0000000..0690cfb
--- /dev/null
+++ b/libqblock/libqblock-error.h
@@ -0,0 +1,50 @@
+/*
+ * QEMU block layer library
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Wenchao Xia   <xiawenc@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef LIBQBLOCK_ERROR
+#define LIBQBLOCK_ERROR
+
+#include "libqblock-types.h"
+
+#define QB_ERR_MEM_ERR (-1)
+#define QB_ERR_INTERNAL_ERR (-2)
+#define QB_ERR_INVALID_PARAM (-3)
+#define QB_ERR_BLOCK_OUT_OF_RANGE (-100)
+
+/* error handling */
+/**
+ * qb_error_get_human_str: get human readable error string.
+ *
+ * return a human readable string, it would be truncated if buf is not big
+ *  enough.
+ *
+ * @broker: operation broker, must be valid.
+ * @buf: buf to receive the string.
+ * @buf_size: the size of the string buf.
+ */
+DLL_PUBLIC
+void qb_error_get_human_str(struct QBroker *broker,
+                            char *buf, int buf_size);
+
+/**
+ * qb_error_get_errno: get error number, only valid when err_ret is
+ *   QB_ERR_INTERNAL_ERR.
+ *
+ * return negative errno or 0 if last error is not QB_ERR_INTERNAL_ERR.
+ *
+ * @broker: operation broker.
+ */
+DLL_PUBLIC
+int qb_error_get_errno(struct QBroker *broker);
+
+#endif
-- 
1.7.1