core: tokbuf: Dynamically expand token buffer

Signed-off-by: Ian Moffett <ian@mirocom.org>

core/state.c

@@ -48,4 +48,5 @@ state_close(struct cescal_state *state)
     close(state->in_fd);
     state->in_fd = -1;
     ptrbox_destroy(&state->ptrbox);
+    tokbuf_destroy(&state->tokbuf);
 }

core/tokbuf.c

@@ -5,6 +5,7 @@
 
 #include <sys/types.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include <stddef.h>
 #include <string.h>
 #include <errno.h>
@@ -18,20 +19,33 @@ tokbuf_init(struct tokbuf *tokbuf)
         return -1;
     }
 
-    memset(tokbuf->buf, 0, sizeof(tokbuf->buf));
     tokbuf->head = 0;
+    tokbuf->cap = TOKBUF_CAP;
+    tokbuf->buf = malloc(sizeof(struct token) * TOKBUF_CAP);
+    if (tokbuf->buf == NULL) {
+        return -1;
+    }
+
     return 0;
 }
 
 int
 tokbuf_push(struct tokbuf *tokbuf, struct token *tok)
 {
+    void *p;
+
     if (tokbuf == NULL || tok == NULL) {
         return -1;
     }
 
-    if ((tokbuf->head++) >= TOKBUF_CAP - 1) {
-        tokbuf->head = 0;
+    if ((tokbuf->head++) >= tokbuf->cap - 1) {
+        tokbuf->cap += 8;
+        p = realloc(tokbuf->buf, sizeof(struct token) * tokbuf->cap);
+        if (tokbuf->buf == NULL) {
+            return -1;
+        }
+
+        tokbuf->buf = p;
     }
 
     tokbuf->buf[tokbuf->head] = *tok;
@@ -60,3 +74,16 @@ tokbuf_noff(struct tokbuf *tokbuf, size_t noff, struct token *res)
     *res = tokbuf->buf[off];
     return 0;
 }
+
+void
+tokbuf_destroy(struct tokbuf *tokbuf)
+{
+    if (tokbuf == NULL) {
+        return;
+    }
+
+    if (tokbuf->buf != NULL) {
+        free(tokbuf->buf);
+        tokbuf->buf = NULL;
+    }
+}

include/cescal/tokbuf.h

@@ -13,7 +13,8 @@
 #define TOKBUF_CAP 4
 
 struct tokbuf {
-    struct token buf[TOKBUF_CAP];
+    struct token *buf;
+    size_t cap;
     uint8_t head;
 };
 
@@ -47,4 +48,11 @@ int tokbuf_push(struct tokbuf *tokbuf, struct token *tok);
  */
 int tokbuf_noff(struct tokbuf *tokbuf, size_t noff, struct token *res);
 
+/*
+ * Destroy a token buffer
+ *
+ * @tokbuf:  Token buffer to destroy
+ */
+void tokbuf_destroy(struct tokbuf *tokbuf);
+
 #endif  /* !CESCAL_TOKBUF_H */