[PATCH igt 1/2] igt: Split out I/O helpers

[Rob Clark <robdclark@gmail.com>]

From: Rob Clark <robdclark@chromium.org>

Split the readN()/writeN() helpers out into an igt_io module, so they
can be re-used by tests.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 lib/igt_io.c    | 96 +++++++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_io.h    | 33 +++++++++++++++++
 lib/igt_sysfs.c | 45 +++--------------------
 lib/meson.build |  1 +
 4 files changed, 135 insertions(+), 40 deletions(-)
 create mode 100644 lib/igt_io.c
 create mode 100644 lib/igt_io.h

diff --git a/lib/igt_io.c b/lib/igt_io.c
new file mode 100644
index 00000000..ad54cbe5
--- /dev/null
+++ b/lib/igt_io.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "igt_io.h"
+
+/**
+ * SECTION:igt_io
+ * @short_description: Helpers for file I/O
+ * @title: io
+ * @include: igt_io.h
+ *
+ * This library provides helpers for file I/O
+ */
+
+/**
+ * igt_readn:
+ * @fd: the file descriptor
+ * @buf: buffer where the contents will be stored, allocated by the caller
+ * @size: size of the buffer
+ *
+ * Read from fd into provided buffer until the buffer is full or EOF
+ *
+ * Returns:
+ * -errorno on failure or bytes read on success
+ */
+ssize_t igt_readn(int fd, char *buf, size_t len)
+{
+	ssize_t ret;
+	size_t total = 0;
+
+	do {
+		ret = read(fd, buf + total, len - total);
+		if (ret < 0)
+			ret = -errno;
+		if (ret == -EINTR || ret == -EAGAIN)
+			continue;
+		if (ret <= 0)
+			break;
+		total += ret;
+	} while (total != len);
+	return total ?: ret;
+}
+
+/**
+ * igt_writen:
+ * @fd: the file descriptor
+ * @buf: the block with the contents to write
+ * @len: the length to write
+ *
+ * This writes @len bytes from @data to the sysfs file.
+ *
+ * Returns:
+ * -errorno on failure or bytes read on success
+ */
+ssize_t igt_writen(int fd, const char *buf, size_t len)
+{
+	ssize_t ret;
+	size_t total = 0;
+
+	do {
+		ret = write(fd, buf + total, len - total);
+		if (ret < 0)
+			ret = -errno;
+		if (ret == -EINTR || ret == -EAGAIN)
+			continue;
+		if (ret <= 0)
+			break;
+		total += ret;
+	} while (total != len);
+	return total ?: ret;
+}
diff --git a/lib/igt_io.h b/lib/igt_io.h
new file mode 100644
index 00000000..eb9ffee1
--- /dev/null
+++ b/lib/igt_io.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef __IGT_IO_H__
+#define __IGT_IO_H__
+
+#include <stdio.h>
+
+ssize_t igt_readn(int fd, char *buf, size_t len);
+ssize_t igt_writen(int fd, const char *buf, size_t len);
+
+#endif /* __IGT_IO_H__ */
diff --git a/lib/igt_sysfs.c b/lib/igt_sysfs.c
index ee75e3ef..f8ef23e2 100644
--- a/lib/igt_sysfs.c
+++ b/lib/igt_sysfs.c
@@ -42,6 +42,7 @@
 #include "igt_core.h"
 #include "igt_sysfs.h"
 #include "igt_device.h"
+#include "igt_io.h"
 
 /**
  * SECTION:igt_sysfs
@@ -53,42 +54,6 @@
  * provides basic support for like igt_sysfs_open().
  */
 
-static ssize_t readN(int fd, char *buf, size_t len)
-{
-	ssize_t ret;
-	size_t total = 0;
-
-	do {
-		ret = read(fd, buf + total, len - total);
-		if (ret < 0)
-			ret = -errno;
-		if (ret == -EINTR || ret == -EAGAIN)
-			continue;
-		if (ret <= 0)
-			break;
-		total += ret;
-	} while (total != len);
-	return total ?: ret;
-}
-
-static ssize_t writeN(int fd, const char *buf, size_t len)
-{
-	ssize_t ret;
-	size_t total = 0;
-
-	do {
-		ret = write(fd, buf + total, len - total);
-		if (ret < 0)
-			ret = -errno;
-		if (ret == -EINTR || ret == -EAGAIN)
-			continue;
-		if (ret <= 0)
-			break;
-		total += ret;
-	} while (total != len);
-	return total ?: ret;
-}
-
 /**
  * igt_sysfs_path:
  * @device: fd of the device
@@ -159,7 +124,7 @@ int igt_sysfs_write(int dir, const char *attr, const void *data, int len)
 	if (igt_debug_on(fd < 0))
 		return -errno;
 
-	len = writeN(fd, data, len);
+	len = igt_writen(fd, data, len);
 	close(fd);
 
 	return len;
@@ -185,7 +150,7 @@ int igt_sysfs_read(int dir, const char *attr, void *data, int len)
 	if (igt_debug_on(fd < 0))
 		return -errno;
 
-	len = readN(fd, data, len);
+	len = igt_readn(fd, data, len);
 	close(fd);
 
 	return len;
@@ -237,7 +202,7 @@ char *igt_sysfs_get(int dir, const char *attr)
 	if (igt_debug_on(!buf))
 		goto out;
 
-	while ((ret = readN(fd, buf + offset, rem)) == rem) {
+	while ((ret = igt_readn(fd, buf + offset, rem)) == rem) {
 		char *newbuf;
 
 		newbuf = realloc(buf, 2*len);
@@ -330,7 +295,7 @@ int igt_sysfs_vprintf(int dir, const char *attr, const char *fmt, va_list ap)
 		}
 	}
 
-	ret = writeN(fd, buf, ret);
+	ret = igt_writen(fd, buf, ret);
 
 	close(fd);
 	if (buf != stack)
diff --git a/lib/meson.build b/lib/meson.build
index 297b0ad2..b9568a71 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -19,6 +19,7 @@ lib_sources = [
 	'igt_aux.c',
 	'igt_gt.c',
 	'igt_halffloat.c',
+	'igt_io.c',
 	'igt_matrix.c',
 	'igt_params.c',
 	'igt_perf.c',
-- 
2.33.1