core: tokbuf: Fix up token buffer

Signed-off-by: Chloe M. <chloe@mirocom.org>

core/tokbuf.c

@@ -29,26 +29,48 @@ tokbuf_init(struct tokbuf *tokbuf)
     return 0;
 }
 
+#include <stdio.h>
+
 int
 tokbuf_push(struct tokbuf *tokbuf, struct token *tok)
 {
     void *p;
+    size_t newcap;
 
     if (tokbuf == NULL || tok == NULL) {
         return -1;
     }
 
-    if ((tokbuf->head++) >= tokbuf->cap - 1) {
-        tokbuf->cap += 8;
-        p = realloc(tokbuf->buf, sizeof(struct token) * tokbuf->cap);
-        if (tokbuf->buf == NULL) {
+    if (tokbuf->head >= tokbuf->cap) {
+        newcap = tokbuf->cap * 8;
+        p = realloc(tokbuf->buf, sizeof(struct token) * newcap);
+        if (p == NULL) {
             return -1;
         }
 
         tokbuf->buf = p;
+        tokbuf->cap = newcap;
     }
 
-    tokbuf->buf[tokbuf->head] = *tok;
+    printf("%d %d\n", tokbuf->head, tok->type);
+    tokbuf->buf[tokbuf->head++] = *tok;
+    return 0;
+}
+
+int
+tokbuf_pop(struct tokbuf *tokbuf, struct token *res)
+{
+    if (tokbuf == NULL || res == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    if (tokbuf->head >= 0) {
+        errno = EAGAIN;
+        return -1;
+    }
+
+    *res = tokbuf->buf[tokbuf->head--];
     return 0;
 }
 
@@ -62,11 +84,6 @@ tokbuf_noff(struct tokbuf *tokbuf, size_t noff, struct token *res)
         return -1;
     }
 
-    if (noff == 0) {
-        *res = tokbuf->buf[tokbuf->head + 1];
-        return 0;
-    }
-
     if ((off = (tokbuf->head - noff + 1)) < 0) {
         off = 0;
     }

include/cescal/tokbuf.h

@@ -37,6 +37,16 @@ int tokbuf_init(struct tokbuf *tokbuf);
  */
 int tokbuf_push(struct tokbuf *tokbuf, struct token *tok);
 
+/*
+ * Pop a token from the token buffer
+ *
+ * @tokbuf:  Token buffer to pop from
+ * @res:     Result is written here
+ *
+ * Returns zero on success
+ */
+int tokbuf_pop(struct tokbuf *tokbuf, struct token *res);
+
 /*
  * Peek at the token buffer from a negative offset backwards
  *