Changeset 80e9e5e in mainline for uspace/lib/c/generic/vfs/vfs.c

Timestamp:

2011-07-27T01:54:34Z (13 years ago)

Author:

Petr Koupy <petr.koupy@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

0837ab4

Parents:

c936c7f (diff), 75aa59a (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge mainline changes.

File:

• uspace/lib/c/generic/vfs/vfs.c (modified) (1 diff)

uspace/lib/c/generic/vfs/vfs.c

@@ -417 +417 @@
 }
 
+/** Read entire buffer.
+ *
+ * In face of short reads this function continues reading until either
+ * the entire buffer is read or no more data is available (at end of file).
+ *
+ * @param fildes        File descriptor
+ * @param buf           Buffer, @a nbytes bytes long
+ * @param nbytes        Number of bytes to read
+ *
+ * @return              On success, positive number of bytes read.
+ *                      On failure, negative error code from read().
+ */
+ssize_t read_all(int fildes, void *buf, size_t nbyte)
+{
+        ssize_t cnt = 0;
+        size_t nread = 0;
+        uint8_t *bp = (uint8_t *) buf;
+
+        do {
+                bp += cnt;
+                nread += cnt;
+                cnt = read(fildes, bp, nbyte - nread);
+        } while (cnt > 0 && (nbyte - nread - cnt) > 0);
+
+        if (cnt < 0)
+                return cnt;
+
+        return nread + cnt;
+}
+
+/** Write entire buffer.
+ *
+ * This function fails if it cannot write exactly @a len bytes to the file.
+ *
+ * @param fildes        File descriptor
+ * @param buf           Data, @a nbytes bytes long
+ * @param nbytes        Number of bytes to write
+ *
+ * @return              EOK on error, return value from write() if writing
+ *                      failed.
+ */
+ssize_t write_all(int fildes, const void *buf, size_t nbyte)
+{
+        ssize_t cnt = 0;
+        ssize_t nwritten = 0;
+        const uint8_t *bp = (uint8_t *) buf;
+
+        do {
+                bp += cnt;
+                nwritten += cnt;
+                cnt = write(fildes, bp, nbyte - nwritten);
+        } while (cnt > 0 && ((ssize_t )nbyte - nwritten - cnt) > 0);
+
+        if (cnt < 0)
+                return cnt;
+
+        if ((ssize_t)nbyte - nwritten - cnt > 0)
+                return EIO;
+
+        return nbyte;
+}
+
 int fsync(int fildes)
 {