Re: [Qemu-devel] [PATCH V2 1/6] libqblock API design

[Wenchao Xia]

于 2012-9-12 16:19, Kevin Wolf 写道:

Am 11.09.2012 22:28, schrieb Blue Swirl:

On Mon, Sep 10, 2012 at 8:26 AM, Wenchao Xia <xiaw...@linux.vnet.ibm.com> wrote:

   This patch contains the major APIs in the library.
Important APIs:
   1 QBroker. These structure was used to retrieve errors, every thread must
create one first, later maybe thread related staff could be added into it.
   2 QBlockState. It stands for an block image object.
   3 QBlockStaticInfo. It contains static information such as location, backing
file, size.
   4 ABI was kept with reserved members.
   5 Sync I/O. It is similar to C file open, read, write and close operations.

Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com>
---
  libqblock/libqblock.c | 1077 +++++++++++++++++++++++++++++++++++++++++++++++++
  libqblock/libqblock.h |  292 +++++++++++++
  2 files changed, 1369 insertions(+), 0 deletions(-)
  create mode 100644 libqblock/libqblock.c
  create mode 100644 libqblock/libqblock.h

diff --git a/libqblock/libqblock.c b/libqblock/libqblock.c
new file mode 100644
index 0000000..133ac0f
--- /dev/null
+++ b/libqblock/libqblock.c
@@ -0,0 +1,1077 @@
+/*
+ * QEMU block layer library
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Wenchao Xia   <xiaw...@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 <unistd.h>
+#include <stdarg.h>
+
+#include "libqblock.h"
+#include "libqblock-internal.h"
+
+#include "qemu-aio.h"
+
+struct LibqblockGlobalData {
+    int init_flag;
+};
+
+struct LibqblockGlobalData g_libqblock_data;
+
+__attribute__((constructor))
+static void libqblock_init(void)
+{
+    if (g_libqblock_data.init_flag == 0) {
+        bdrv_init();
+        qemu_init_main_loop();
+    }
+    g_libqblock_data.init_flag = 1;
+}
+
+const char *qb_fmttype2str(enum QBlockFmtType fmt_type)
+{
+    const char *ret = NULL;
+    switch (fmt_type) {
+    case QB_FMT_COW:
+        ret = "cow";
+        break;
+    case QB_FMT_QED:
+        ret = "qed";
+        break;
+    case QB_FMT_QCOW:
+        ret = "qcow";
+        break;
+    case QB_FMT_QCOW2:
+        ret = "qcow2";
+        break;
+    case QB_FMT_RAW:
+        ret = "raw";
+        break;
+    case QB_FMT_RBD:
+        ret = "rbd";
+        break;
+    case QB_FMT_SHEEPDOG:
+        ret = "sheepdog";
+        break;
+    case QB_FMT_VDI:
+        ret = "vdi";
+        break;
+    case QB_FMT_VMDK:
+        ret = "vmdk";
+        break;
+    case QB_FMT_VPC:
+        ret = "vpc";
+        break;
+    default:
+        break;
+    }
+    return ret;
+}
+
+enum QBlockFmtType qb_str2fmttype(const char *fmt_str)
+{
+    enum QBlockFmtType ret = QB_FMT_NONE;
+    if (0 == strcmp(fmt_str, "cow")) {

This order is not common in QEMU.

How about just changing the whole thing to a table that maps
QBlockFmtType to strings, and then both conversion functions could just
search that table?

  Good idea, will go this way.

+        ret = QB_FMT_COW;
+    } else if (0 == strcmp(fmt_str, "qed")) {
+        ret = QB_FMT_QED;
+    } else if (0 == strcmp(fmt_str, "qcow")) {
+        ret = QB_FMT_QCOW;
+    } else if (0 == strcmp(fmt_str, "qcow2")) {
+        ret = QB_FMT_QCOW2;
+    } else if (0 == strcmp(fmt_str, "raw")) {
+        ret = QB_FMT_RAW;
+    } else if (0 == strcmp(fmt_str, "rbd")) {
+        ret = QB_FMT_RBD;
+    } else if (0 == strcmp(fmt_str, "sheepdog")) {
+        ret = QB_FMT_SHEEPDOG;
+    } else if (0 == strcmp(fmt_str, "vdi")) {
+        ret = QB_FMT_VDI;
+    } else if (0 == strcmp(fmt_str, "vmdk")) {
+        ret = QB_FMT_VMDK;
+    } else if (0 == strcmp(fmt_str, "vpc")) {
+        ret = QB_FMT_VPC;
+    }
+    return ret;
+}

Kevin

--
Best Regards

Wenchao Xia