dstring: Add some exact-size utility functions

2 files changed, 135 insertions, 21 deletions

diff --git a/src/dstring.c b/src/dstring.c
index f019ba9..dada70b 100644
--- a/src/dstring.c
+++ b/src/dstring.c
@@ -54,12 +54,18 @@ char *dstralloc(size_t capacity) {
 }
 
 char *dstrdup(const char *str) {
-	size_t len = strlen(str);
-	return dstralloc_impl(len, len, str);
+	return dstrxdup(str, strlen(str));
 }
 
 char *dstrndup(const char *str, size_t n) {
-	size_t len = strnlen(str, n);
+	return dstrxdup(str, strnlen(str, n));
+}
+
+char *dstrddup(const char *dstr) {
+	return dstrxdup(dstr, dstrlen(dstr));
+}
+
+char *dstrxdup(const char *str, size_t len) {
 	return dstralloc_impl(len, len, str);
 }
 
@@ -98,37 +104,56 @@ int dstresize(char **dstr, size_t length) {
 	struct dstring *header = dstrheader(*dstr);
 	header->length = length;
 	header->data[length] = '\0';
-
 	return 0;
 }
 
-/** Common implementation of dstr{cat,ncat,app}. */
-static int dstrcat_impl(char **dest, const char *src, size_t srclen) {
+int dstrcat(char **dest, const char *src) {
+	return dstrxcat(dest, src, strlen(src));
+}
+
+int dstrncat(char **dest, const char *src, size_t n) {
+	return dstrxcat(dest, src, strnlen(src, n));
+}
+
+int dstrdcat(char **dest, const char *src) {
+	return dstrxcat(dest, src, dstrlen(src));
+}
+
+int dstrxcat(char **dest, const char *src, size_t len) {
 	size_t oldlen = dstrlen(*dest);
-	size_t newlen = oldlen + srclen;
+	size_t newlen = oldlen + len;
 
 	if (dstresize(dest, newlen) != 0) {
 		return -1;
 	}
 
-	memcpy(*dest + oldlen, src, srclen);
+	memcpy(*dest + oldlen, src, len);
 	return 0;
 }
 
-int dstrcat(char **dest, const char *src) {
-	return dstrcat_impl(dest, src, strlen(src));
+int dstrapp(char **str, char c) {
+	return dstrxcat(str, &c, 1);
 }
 
-int dstrncat(char **dest, const char *src, size_t n) {
-	return dstrcat_impl(dest, src, strnlen(src, n));
+int dstrcpy(char **dest, const char *src) {
+	return dstrxcpy(dest, src, strlen(src));
 }
 
-int dstrdcat(char **dest, const char *src) {
-	return dstrcat_impl(dest, src, dstrlen(src));
+int dstrncpy(char **dest, const char *src, size_t n) {
+	return dstrxcpy(dest, src, strnlen(src, n));
 }
 
-int dstrapp(char **str, char c) {
-	return dstrcat_impl(str, &c, 1);
+int dstrdcpy(char **dest, const char *src) {
+	return dstrxcpy(dest, src, dstrlen(src));
+}
+
+int dstrxcpy(char **dest, const char *src, size_t len) {
+	if (dstresize(dest, len) != 0) {
+		return -1;
+	}
+
+	memcpy(*dest, src, len);
+	return 0;
 }
 
 char *dstrprintf(const char *format, ...) {
diff --git a/src/dstring.h b/src/dstring.h
index ee3b345..2673f1b 100644
--- a/src/dstring.h
+++ b/src/dstring.h
@@ -39,11 +39,30 @@ char *dstrdup(const char *str);
 char *dstrndup(const char *str, size_t n);
 
 /**
+ * Create a dynamic copy of a dynamic string.
+ *
+ * @param dstr
+ *         The dynamic string to copy.
+ */
+char *dstrddup(const char *dstr);
+
+/**
+ * Create an exact-sized dynamic copy of a string.
+ *
+ * @param str
+ *         The string to copy.
+ * @param len
+ *         The length of the string, which may include internal NUL bytes.
+ */
+char *dstrxdup(const char *str, size_t len);
+
+/**
  * Get a dynamic string's length.
  *
  * @param dstr
  *         The string to measure.
- * @return The length of dstr.
+ * @return
+ *         The length of dstr.
  */
 size_t dstrlen(const char *dstr);
 
@@ -54,7 +73,8 @@ size_t dstrlen(const char *dstr);
  *         The dynamic string to preallocate.
  * @param capacity
  *         The new capacity for the string.
- * @return 0 on success, -1 on failure.
+ * @return
+ *         0 on success, -1 on failure.
  */
 int dstreserve(char **dstr, size_t capacity);
 
@@ -65,7 +85,8 @@ int dstreserve(char **dstr, size_t capacity);
  *         The dynamic string to resize.
  * @param length
  *         The new length for the dynamic string.
- * @return 0 on success, -1 on failure.
+ * @return
+ *         0 on success, -1 on failure.
  */
 int dstresize(char **dstr, size_t length);
 
@@ -89,7 +110,8 @@ int dstrcat(char **dest, const char *src);
  *         The string to append.
  * @param n
  *         The maximum number of characters to take from src.
- * @return 0 on success, -1 on failure.
+ * @return
+ *         0 on success, -1 on failure.
  */
 int dstrncat(char **dest, const char *src, size_t n);
 
@@ -106,17 +128,84 @@ int dstrncat(char **dest, const char *src, size_t n);
 int dstrdcat(char **dest, const char *src);
 
 /**
+ * Append to a dynamic string.
+ *
+ * @param dest
+ *         The destination dynamic string.
+ * @param src
+ *         The string to append.
+ * @param len
+ *         The exact number of characters to take from src.
+ * @return
+ *         0 on success, -1 on failure.
+ */
+int dstrxcat(char **dest, const char *src, size_t len);
+
+/**
  * Append a single character to a dynamic string.
  *
  * @param str
  *         The string to append to.
  * @param c
  *         The character to append.
- * @return 0 on success, -1 on failure.
+ * @return
+ *         0 on success, -1 on failure.
  */
 int dstrapp(char **str, char c);
 
 /**
+ * Copy a string into a dynamic string.
+ *
+ * @param dest
+ *         The destination dynamic string.
+ * @param src
+ *         The string to copy.
+ * @returns
+ *         0 on success, -1 on failure.
+ */
+int dstrcpy(char **dest, const char *str);
+
+/**
+ * Copy a dynamic string into another one.
+ *
+ * @param dest
+ *         The destination dynamic string.
+ * @param src
+ *         The dynamic string to copy.
+ * @returns
+ *         0 on success, -1 on failure.
+ */
+int dstrdcpy(char **dest, const char *str);
+
+/**
+ * Copy a string into a dynamic string.
+ *
+ * @param dest
+ *         The destination dynamic string.
+ * @param src
+ *         The dynamic string to copy.
+ * @param n
+ *         The maximum number of characters to take from src.
+ * @returns
+ *         0 on success, -1 on failure.
+ */
+int dstrncpy(char **dest, const char *str, size_t n);
+
+/**
+ * Copy a string into a dynamic string.
+ *
+ * @param dest
+ *         The destination dynamic string.
+ * @param src
+ *         The dynamic string to copy.
+ * @param len
+ *         The exact number of characters to take from src.
+ * @returns
+ *         0 on success, -1 on failure.
+ */
+int dstrxcpy(char **dest, const char *str, size_t len);
+
+/**
  * Create a dynamic string from a format string.
  *
  * @param format