[Qemu-devel] [PATCH 02/16] qio: create new qio_channel_read_all

[Juan Quintela]

It is the symmetric function from qio_channel_write_all

Signed-off-by: Juan Quintela <address@hidden>
---
 include/io/channel.h | 23 +++++++++++++++++++++++
 io/channel.c         | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/include/io/channel.h b/include/io/channel.h
index f786c4f..2f55831 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -269,6 +269,29 @@ ssize_t qio_channel_writev_full(QIOChannel *ioc,
                                 Error **errp);
 
 /**
+ * qio_channel_readv_all:
+ * @ioc: the channel object
+ * @iov: the array of memory regions to read data into
+ * @niov: the length of the @iov array
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Read data from the IO channel, storing it in the
+ * memory regions referenced by @iov. Each element
+ * in the @iov will be fully populated with data
+ * before the next one is used. The @niov parameter
+ * specifies the total number of elements in @iov.
+ *
+ * Returns: the number of bytes read, or -1 on error,
+ * or QIO_CHANNEL_ERR_BLOCK if no data is available
+ * and the channel is non-blocking
+ */
+ssize_t qio_channel_readv_all(QIOChannel *ioc,
+                              const struct iovec *iov,
+                              size_t niov,
+                              Error **errp);
+
+
+/**
  * qio_channel_writev_all:
  * @ioc: the channel object
  * @iov: the array of memory regions to write data from
diff --git a/io/channel.c b/io/channel.c
index c5a1bd5..82203ef 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -87,6 +87,43 @@ ssize_t qio_channel_writev_full(QIOChannel *ioc,
 
 
 
+ssize_t qio_channel_readv_all(QIOChannel *ioc,
+                              const struct iovec *iov,
+                              size_t niov,
+                              Error **errp)
+{
+    ssize_t done = 0;
+    struct iovec *local_iov = g_new(struct iovec, niov);
+    struct iovec *local_iov_head = local_iov;
+    unsigned int nlocal_iov = niov;
+
+    nlocal_iov = iov_copy(local_iov, nlocal_iov,
+                          iov, niov,
+                          0, iov_size(iov, niov));
+
+    while (nlocal_iov > 0) {
+        ssize_t len;
+        len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp);
+        if (len == QIO_CHANNEL_ERR_BLOCK) {
+            qio_channel_wait(ioc, G_IO_OUT);
+            continue;
+        }
+        if (len < 0) {
+            error_setg_errno(errp, EIO,
+                             "Channel was not able to read full iov");
+            done = -1;
+            goto cleanup;
+        }
+
+        iov_discard_front(&local_iov, &nlocal_iov, len);
+        done += len;
+    }
+
+ cleanup:
+    g_free(local_iov_head);
+    return done;
+}
+
 ssize_t qio_channel_writev_all(QIOChannel *ioc,
                                const struct iovec *iov,
                                size_t niov,
-- 
2.9.3