forgot to add lib/Utils/copyfd.cpp

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 107 insertions, 0 deletions

diff --git a/lib/Utils/copyfd.cpp b/lib/Utils/copyfd.cpp
new file mode 100644
index 00000000..cda52b03
--- /dev/null
+++ b/lib/Utils/copyfd.cpp
@@ -0,0 +1,107 @@
+/*
+ * Utility routines.
+ *
+ * Licensed under GPLv2, see file COPYING in this tarball for details.
+ */
+#include "abrtlib.h"
+
+#define CONFIG_FEATURE_COPYBUF_KB 4
+
+static const char msg_write_error[] = "write error";
+static const char msg_read_error[] = "read error";
+
+static off_t full_fd_action(int src_fd, int dst_fd, off_t size)
+{
+	int status = -1;
+	off_t total = 0;
+#if CONFIG_FEATURE_COPYBUF_KB <= 4
+	char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024];
+	enum { buffer_size = sizeof(buffer) };
+#else
+	char *buffer;
+	int buffer_size;
+
+	/* We want page-aligned buffer, just in case kernel is clever
+	 * and can do page-aligned io more efficiently */
+	buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024,
+			PROT_READ | PROT_WRITE,
+			MAP_PRIVATE | MAP_ANON,
+			/* ignored: */ -1, 0);
+	buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024;
+	if (buffer == MAP_FAILED) {
+		buffer = alloca(4 * 1024);
+		buffer_size = 4 * 1024;
+	}
+#endif
+
+	if (src_fd < 0)
+		goto out;
+
+	if (!size) {
+		size = buffer_size;
+		status = 1; /* copy until eof */
+	}
+
+	while (1) {
+		ssize_t rd;
+
+		rd = safe_read(src_fd, buffer, size > buffer_size ? buffer_size : size);
+
+		if (!rd) { /* eof - all done */
+			status = 0;
+			break;
+		}
+		if (rd < 0) {
+			perror_msg(msg_read_error);
+			break;
+		}
+		/* dst_fd == -1 is a fake, else... */
+		if (dst_fd >= 0) {
+			ssize_t wr = full_write(dst_fd, buffer, rd);
+			if (wr < rd) {
+				perror_msg(msg_write_error);
+				break;
+			}
+		}
+		total += rd;
+		if (status < 0) { /* if we aren't copying till EOF... */
+			size -= rd;
+			if (!size) {
+				/* 'size' bytes copied - all done */
+				status = 0;
+				break;
+			}
+		}
+	}
+ out:
+
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+	if (buffer_size != 4 * 1024)
+		munmap(buffer, buffer_size);
+#endif
+	return status ? -1 : total;
+}
+
+off_t copyfd_size(int fd1, int fd2, off_t size)
+{
+	if (size) {
+		return full_fd_action(fd1, fd2, size);
+	}
+	return 0;
+}
+
+void copyfd_exact_size(int fd1, int fd2, off_t size)
+{
+	off_t sz = copyfd_size(fd1, fd2, size);
+	if (sz == size)
+		return;
+	if (sz != -1)
+		error_msg_and_die("short read");
+	/* if sz == -1, copyfd_XX already complained */
+	xfunc_die();
+}
+
+off_t copyfd_eof(int fd1, int fd2)
+{
+	return full_fd_action(fd1, fd2, 0);
+}