From 379fde98409617ac4a094ccdd319a55943820d2a Mon Sep 17 00:00:00 2001
From: Mohamed Aslan <maslan@sce.carleton.ca>
Date: Fri, 3 Nov 2017 17:41:37 -0600
Subject: [PATCH] implement missing function in buffer.c

---
 buffer.c      | 45 +++++++++++++++++++++++++++++++++++++++++++--
 regress/buf.c | 32 ++++++++++++++++++++++++++------
 2 files changed, 69 insertions(+), 8 deletions(-)

diff --git a/buffer.c b/buffer.c
index 3f2cab6..a3ff83b 100644
--- a/buffer.c
+++ b/buffer.c
@@ -23,14 +23,18 @@
 struct rbuffer *
 rbuffer_new(size_t capacity)
 {
-	struct rbuffer *rbuf = malloc(sizeof(struct rbuffer));
+	struct rbuffer *rbuf;
 
+	rbuf = malloc(sizeof(struct rbuffer));
 	if (rbuf == NULL)
 		goto ret;
-
 	rbuf->rb_capacity = capacity > 0 ? capacity : BUFSIZ;
 	rbuf->rb_len = 0;
 	rbuf->rb_data = reallocarray(NULL, rbuf->rb_capacity, sizeof(char));
+	if (rbuf->rb_data == NULL) {
+		free(rbuf);
+		goto ret;
+	}
 	rbuf->rb_wp = rbuf->rb_data;
 	rbuf->rb_rp = rbuf->rb_data;
 ret:
@@ -108,4 +112,41 @@ rbuffer_read(struct rbuffer *rbuf, size_t len)
 	return str;
 }
 
+static int
+rbuffer_find(struct rbuffer *rbuf, char ch, size_t *len)
+{
+	char	*ptr = rbuf->rb_rp;
+	size_t	 n, m;
+
+	n = MIN(rbuf->rb_len, (rbuf->rb_data + rbuf->rb_capacity) - rbuf->rb_rp);
+	m = rbuf->rb_len - n;
+	for (ptr = rbuf->rb_rp ; n-- ; ptr++) {
+		if (*ptr == ch) {
+			*len = rbuf->rb_len - n - m;
+			return 1;
+		}
+	}
+	for (ptr = rbuf->rb_data ; m-- ; ptr++) {
+		if (*ptr == ch) {
+			*len = rbuf->rb_len - m;
+			return 1;
+		}
+	}
+	return 0;
+}
 
+char *
+rbuffer_readline(struct rbuffer *rbuf)
+{
+	char	*str;
+	size_t	 n;
+
+	if (!rbuf->rb_len)
+		return NULL;
+	if (rbuffer_find(rbuf, '\n', &n)) {
+		str = rbuffer_read(rbuf, n);
+		str[n - 1] = '\0';
+		return str;
+	}
+	return NULL;
+}
diff --git a/regress/buf.c b/regress/buf.c
index c1db5df..1ee41cb 100644
--- a/regress/buf.c
+++ b/regress/buf.c
@@ -25,15 +25,12 @@ main(int argc, char **argv)
 {
 	struct rbuffer *rb;
 	char *str;
-	char *str1 = "1234567890XY";
-	char *str2 = "ABCDEFGHI";
-	char *str3 = "J";
 	int i;
 
 	rb = rbuffer_new(10);
 	if (rb == NULL)
 		return 1;
-	rbuffer_write(rb, str1, strlen(str1));
+	rbuffer_write(rb, "1234567890XY", 12);
 
 	/* test: insertion */
 	if (strncmp(rb->rb_data, "XY34567890", 10)) {
@@ -44,7 +41,7 @@ main(int argc, char **argv)
 		return 1;
 	}
 
-	rbuffer_write(rb, str2, strlen(str2));
+	rbuffer_write(rb, "ABCDEFGHI", 9);
 	if (strncmp(rb->rb_data, "IYABCDEFGH", 10)) {
 		printf("FAILED: ");
 		for (i = 0 ; i < rb->rb_capacity ; i++)
@@ -53,7 +50,7 @@ main(int argc, char **argv)
 		return 1;
 	}
 
-	rbuffer_write(rb, str3, strlen(str3));
+	rbuffer_write(rb, "J", 1);
 	if (strncmp(rb->rb_data, "IJABCDEFGH", 10)) {
 		printf("FAILED: ");
 		for (i = 0 ; i < rb->rb_capacity ; i++)
@@ -106,6 +103,29 @@ main(int argc, char **argv)
 	}
 	free(str);
 
+	/* test: readline */
+	rbuffer_write(rb, "QWERTYUIOP\n", 11);
+	str = rbuffer_readline(rb);
+	if (str == NULL)
+		return 1;
+	if (strncmp(str, "WERTYUIOP", 10)) {
+		printf("FAILED: ");
+		for (i = 0 ; i < 10 ; i++)
+			printf("%c ", str[i]);
+		printf("\n");
+		return 1;
+	}
+	free(str);
+
+	rbuffer_write(rb, "\n", 1);
+	str = rbuffer_readline(rb);
+	if (str == NULL)
+		return 1;
+	if (strcmp(str, "")) {
+		printf("FAILED\n");
+		return 1;
+	}
+
 	rbuffer_free(rb);
 
 	return 0;
-- 
2.11.4.GIT