X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/e7eb3a2744aa45179daea235800753d3d1955338..19007e89957054b4af8667f85c0ec8d95f2001d6:/lib/kvp.c

diff --git a/lib/kvp.c b/lib/kvp.c
index 13a5cc4..45aa03c 100644
--- a/lib/kvp.c
+++ b/lib/kvp.c
@@ -15,6 +15,13 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+/** @file lib/kvp.c
+ * @brief Linked list of key-value pairs
+ *
+ * Also supports URL encoding/decoding (of raw strings and kvp lists).
+ *
+ * For large sets of keys, see @ref lib/hash.c.
+ */
 
 #include "common.h"
 
@@ -25,6 +32,12 @@
 #include "hex.h"
 #include "sink.h"
 
+/** @brief Decode a URL-encoded string to a ink
+ * @param sink Where to store result
+ * @param ptr Start of string
+ * @param n Length of string
+ * @return 0 on success, non-0 if string could not be decoded or sink write failed
+ */
 int urldecode(struct sink *sink, const char *ptr, size_t n) {
   int c, d1, d2;
   
@@ -50,6 +63,11 @@ int urldecode(struct sink *sink, const char *ptr, size_t n) {
   return 0;
 }
 
+/** @brief URL-decode a string
+ * @param ptr Start of URL-encoded string
+ * @param n Length of @p ptr
+ * @return Decoded string (0-terminated)
+ */
 static char *decode(const char *ptr, size_t n) {
   struct dynstr d;
   struct sink *s;
@@ -62,6 +80,15 @@ static char *decode(const char *ptr, size_t n) {
   return d.vec;
 }
 
+/** @brief Decode a URL-decoded key-value pair list
+ * @param ptr Start of input string
+ * @param n Length of input string
+ * @return @ref kvp of values from input
+ *
+ * The KVP is in the same order as the original input.
+ *
+ * If the original input contains duplicates names, so will the KVP.
+ */
 struct kvp *kvp_urldecode(const char *ptr, size_t n) {
   struct kvp *kvp, **kk = &kvp, *k;
   const char *q, *r, *top = ptr + n, *next;
@@ -85,6 +112,12 @@ struct kvp *kvp_urldecode(const char *ptr, size_t n) {
   return kvp;
 }
 
+/** @brief URL-encode a string to a sink
+ * @param sink Where to send output
+ * @param s String to encode
+ * @param n Length of string to encode
+ * @return 0 on success or non-0 if sink write failed
+ */
 int urlencode(struct sink *sink, const char *s, size_t n) {
   unsigned char c;
 
@@ -146,6 +179,11 @@ char *urldecodestring(const char *s, size_t ns) {
   return d.vec;
 }
 
+/** @brief URL-encode a KVP
+ * @param kvp Linked list to encode
+ * @param np Where to store length (or NULL)
+ * @return Newly created string
+ */
 char *kvp_urlencode(const struct kvp *kvp, size_t *np) {
   struct dynstr d;
   struct sink *sink;
@@ -166,6 +204,20 @@ char *kvp_urlencode(const struct kvp *kvp, size_t *np) {
   return d.vec;
 }
 
+/** @brief Set or remove a value in a @ref kvp
+ * @param kvpp Address of KVP head to modify
+ * @param name Key to search for
+ * @param value New value or NULL to delete
+ * @return 1 if any change was made otherwise 0
+ *
+ * If @p value is not NULL then the first matching key is replaced; if
+ * there was no matching key a new one is added at the end.
+ *
+ * If @p value is NULL then the first matching key is removed.
+ *
+ * If anything actually changes the return value is 1.  If no actual
+ * change is made then 0 is returned instead.
+ */
 int kvp_set(struct kvp **kvpp, const char *name, const char *value) {
   struct kvp *k, **kk;
 
@@ -193,12 +245,29 @@ int kvp_set(struct kvp **kvpp, const char *name, const char *value) {
   }
 }
 
+/** @brief Look up a value in a @ref kvp
+ * @param kvp Head of KVP linked list
+ * @param name Key to search for
+ * @return Value or NULL
+ *
+ * The returned value is owned by the KVP so must not be modified or
+ * freed.
+ */
 const char *kvp_get(const struct kvp *kvp, const char *name) {
   for(;kvp && strcmp(kvp->name, name); kvp = kvp->next)
     ;
   return kvp ? kvp->value : 0;
 }
 
+/** @brief Construct a KVP from arguments
+ * @param name First name
+ * @return Newly created KVP
+ *
+ * Arguments must come in name/value pairs and must be followed by a (char *)0.
+ *
+ * The order of the new KVP is not formally defined though the test
+ * programs rely on it nonetheless so update them if you change it.
+ */
 struct kvp *kvp_make(const char *name, ...) {
   const char *value;
   struct kvp *kvp = 0, *k;
@@ -209,7 +278,7 @@ struct kvp *kvp_make(const char *name, ...) {
     value = va_arg(ap, const char *);
     k = xmalloc(sizeof *k);
     k->name = name;
-    k->value = value ? xstrdup(value) : value;
+    k->value = value ? xstrdup(value) : "";
     k->next = kvp;
     kvp = k;
     name = va_arg(ap, const char *);