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-rw-r--r--include/io/channel.h53
-rw-r--r--io/channel.c48
2 files changed, 93 insertions, 8 deletions
diff --git a/include/io/channel.h b/include/io/channel.h
index 8f25893c45..3995e243a3 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -269,6 +269,36 @@ ssize_t qio_channel_writev_full(QIOChannel *ioc,
                                 Error **errp);
 
 /**
+ * qio_channel_readv_all_eof:
+ * @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.
+ *
+ * The function will wait for all requested data
+ * to be read, yielding from the current coroutine
+ * if required.
+ *
+ * If end-of-file occurs before any data is read,
+ * no error is reported; otherwise, if it occurs
+ * before all requested data has been read, an error
+ * will be reported.
+ *
+ * Returns: 1 if all bytes were read, 0 if end-of-file
+ *          occurs without data, or -1 on error
+ */
+int qio_channel_readv_all_eof(QIOChannel *ioc,
+                              const struct iovec *iov,
+                              size_t niov,
+                              Error **errp);
+
+/**
  * qio_channel_readv_all:
  * @ioc: the channel object
  * @iov: the array of memory regions to read data into
@@ -383,6 +413,28 @@ ssize_t qio_channel_write(QIOChannel *ioc,
                           Error **errp);
 
 /**
+ * qio_channel_read_all_eof:
+ * @ioc: the channel object
+ * @buf: the memory region to read data into
+ * @buflen: the number of bytes to @buf
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Reads @buflen bytes into @buf, possibly blocking or (if the
+ * channel is non-blocking) yielding from the current coroutine
+ * multiple times until the entire content is read. If end-of-file
+ * occurs immediately it is not an error, but if it occurs after
+ * data has been read it will return an error rather than a
+ * short-read. Otherwise behaves as qio_channel_read().
+ *
+ * Returns: 1 if all bytes were read, 0 if end-of-file occurs
+ *          without data, or -1 on error
+ */
+int qio_channel_read_all_eof(QIOChannel *ioc,
+                             char *buf,
+                             size_t buflen,
+                             Error **errp);
+
+/**
  * qio_channel_read_all:
  * @ioc: the channel object
  * @buf: the memory region to read data into
@@ -401,6 +453,7 @@ int qio_channel_read_all(QIOChannel *ioc,
                          char *buf,
                          size_t buflen,
                          Error **errp);
+
 /**
  * qio_channel_write_all:
  * @ioc: the channel object
diff --git a/io/channel.c b/io/channel.c
index 9e62794cab..ec4b86de7c 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -86,16 +86,16 @@ ssize_t qio_channel_writev_full(QIOChannel *ioc,
 }
 
 
-
-int qio_channel_readv_all(QIOChannel *ioc,
-                          const struct iovec *iov,
-                          size_t niov,
-                          Error **errp)
+int qio_channel_readv_all_eof(QIOChannel *ioc,
+                              const struct iovec *iov,
+                              size_t niov,
+                              Error **errp)
 {
     int ret = -1;
     struct iovec *local_iov = g_new(struct iovec, niov);
     struct iovec *local_iov_head = local_iov;
     unsigned int nlocal_iov = niov;
+    bool partial = false;
 
     nlocal_iov = iov_copy(local_iov, nlocal_iov,
                           iov, niov,
@@ -114,21 +114,43 @@ int qio_channel_readv_all(QIOChannel *ioc,
         } else if (len < 0) {
             goto cleanup;
         } else if (len == 0) {
-            error_setg(errp,
-                       "Unexpected end-of-file before all bytes were read");
+            if (partial) {
+                error_setg(errp,
+                           "Unexpected end-of-file before all bytes were read");
+            } else {
+                ret = 0;
+            }
             goto cleanup;
         }
 
+        partial = true;
         iov_discard_front(&local_iov, &nlocal_iov, len);
     }
 
-    ret = 0;
+    ret = 1;
 
  cleanup:
     g_free(local_iov_head);
     return ret;
 }
 
+int qio_channel_readv_all(QIOChannel *ioc,
+                          const struct iovec *iov,
+                          size_t niov,
+                          Error **errp)
+{
+    int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp);
+
+    if (ret == 0) {
+        ret = -1;
+        error_setg(errp,
+                   "Unexpected end-of-file before all bytes were read");
+    } else if (ret == 1) {
+        ret = 0;
+    }
+    return ret;
+}
+
 int qio_channel_writev_all(QIOChannel *ioc,
                            const struct iovec *iov,
                            size_t niov,
@@ -205,6 +227,16 @@ ssize_t qio_channel_write(QIOChannel *ioc,
 }
 
 
+int qio_channel_read_all_eof(QIOChannel *ioc,
+                             char *buf,
+                             size_t buflen,
+                             Error **errp)
+{
+    struct iovec iov = { .iov_base = buf, .iov_len = buflen };
+    return qio_channel_readv_all_eof(ioc, &iov, 1, errp);
+}
+
+
 int qio_channel_read_all(QIOChannel *ioc,
                          char *buf,
                          size_t buflen,