From: Heng Li <lh3@me.com>
Date: Sun, 30 Nov 2014 00:54:16 +0000 (-0500)
Subject: simplified API
X-Git-Url: http://www.kaiwu.me/postgresql/commit/?a=commitdiff_plain;h=e929200888cf53c7d22164be4b8e3dc36e9b6f0e;p=klib.git

simplified API
---

diff --git a/kson.c b/kson.c
index 204ecac..33d1e6b 100644
--- a/kson.c
+++ b/kson.c
@@ -11,7 +11,7 @@
 
 kson_node_t *kson_parse_core(const char *json, long *_n, int *error, long *parsed_len)
 {
-	long *stack = 0, top = 0, max = 0, n_a = 0, m_a = 0;
+	long *stack = 0, top = 0, max = 0, n_a = 0, m_a = 0, i, j;
 	kson_node_t *a = 0, *u;
 	const char *p, *q;
 
@@ -56,9 +56,9 @@ kson_node_t *kson_parse_core(const char *json, long *_n, int *error, long *parse
 			u = &a[stack[start-1]];
 			u->key = u->v.str;
 			u->n = top - 1 - start;
-			u->v.child = (long*)malloc(u->n * sizeof(long));
+			u->v.child = (kson_ptr_t*)malloc(u->n * sizeof(kson_ptr_t));
 			for (i = start + 1; i < top; ++i)
-				u->v.child[i - start - 1] = stack[i];
+				u->v.child[i - start - 1].i = stack[i];
 			u->type = *p == ']'? KSON_TYPE_BRACKET : KSON_TYPE_BRACE;
 			if ((top = start) == 1) break; // completed one object; remaining characters discarded
 		} else if (*p == ':') {
@@ -95,6 +95,12 @@ kson_node_t *kson_parse_core(const char *json, long *_n, int *error, long *parse
 	if (parsed_len) *parsed_len = p - json;
 	if (top != 1) *error = KSON_ERR_EXTRA_LEFT;
 
+	for (i = 0; i < n_a; ++i) {
+		u = &a[i];
+		for (j = 0; j < (long)u->n; ++j)
+			u->v.child[j].p = &a[u->v.child[j].i];
+	}
+
 	free(stack);
 	*_n = n_a;
 	return a;
@@ -126,16 +132,15 @@ kson_t *kson_parse(const char *json, int *error)
  *** Query ***
  *************/
 
-const kson_node_t *kson_query(const kson_t *kson, int depth, ...)
+const kson_node_t *kson_query(const kson_node_t *p, int depth, ...)
 {
-	const kson_node_t *p = kson->nodes;
 	va_list ap;
 	va_start(ap, depth);
 	while (p && depth > 0) {
 		if (p->type == KSON_TYPE_BRACE) {
-			p = kson_by_key(kson->nodes, p, va_arg(ap, const char*));
+			p = kson_by_key(p, va_arg(ap, const char*));
 		} else if (p->type == KSON_TYPE_BRACKET) {
-			p = kson_by_index(kson->nodes, p, va_arg(ap, long));
+			p = kson_by_index(p, va_arg(ap, long));
 		} else break;
 		--depth;
 	}
@@ -147,7 +152,7 @@ const kson_node_t *kson_query(const kson_t *kson, int depth, ...)
  *** Fromat ***
  **************/
 
-void kson_format_recur(const kson_node_t *nodes, int depth, const kson_node_t *p)
+void kson_format_recur(const kson_node_t *p, int depth)
 {
 	long i;
 	if (p->key) {
@@ -164,7 +169,7 @@ void kson_format_recur(const kson_node_t *nodes, int depth, const kson_node_t *p
 					putchar(',');
 					putchar('\n'); for (i = 0; i <= depth; ++i) fputs("  ", stdout);
 				}
-				kson_format_recur(nodes, depth + 1, &nodes[p->v.child[i]]);
+				kson_format_recur(p->v.child[i].p, depth + 1);
 			}
 			putchar('\n'); for (i = 0; i < depth; ++i) fputs("  ", stdout);
 		}
@@ -178,9 +183,9 @@ void kson_format_recur(const kson_node_t *nodes, int depth, const kson_node_t *p
 	}
 }
 
-void kson_format(const kson_t *kson)
+void kson_format(const kson_node_t *root)
 {
-	kson_format_recur(kson->nodes, 0, kson->nodes);
+	kson_format_recur(root, 0);
 	putchar('\n');
 }
 
@@ -220,9 +225,9 @@ int main(int argc, char *argv[])
 					const kson_node_t *p = kson->nodes;
 					for (i = 2; i < argc && p; ++i) {
 						if (p->type == KSON_TYPE_BRACKET)
-							p = kson_by_index(kson->nodes, p, atoi(argv[i]));
+							p = kson_by_index(p, atoi(argv[i]));
 						else if (p->type == KSON_TYPE_BRACE)
-							p = kson_by_key(kson->nodes, p, argv[i]);
+							p = kson_by_key(p, argv[i]);
 						else p = 0;
 					}
 					if (p) {
@@ -235,7 +240,7 @@ int main(int argc, char *argv[])
 	} else {
 		kson = kson_parse("{'a' : 1,'b':[0,'isn\\'t',true],'d':[{\n}]}", &error);
 		if (error == 0) {
-			const kson_node_t *p = kson_query(kson, 2, "b", 1);
+			const kson_node_t *p = kson_query(kson->nodes, 2, "b", 1);
 			if (p) printf("*** %s\n", p->v.str);
 			else printf("!!! not found\n");
 			kson_format(kson);
diff --git a/kson.h b/kson.h
index 25845ad..d8b7e38 100644
--- a/kson.h
+++ b/kson.h
@@ -14,18 +14,25 @@
 #define KSON_ERR_EXTRA_RIGHT 2
 #define KSON_ERR_NO_KEY      3
 
-typedef struct {
+struct kson_node_s;
+
+typedef union {
+	long i; // this is a temporary variable; don't use it!
+	struct kson_node_s *p;
+} kson_ptr_t;
+
+typedef struct kson_node_s {
 	uint64_t type:3, n:61;
 	char *key;
 	union {
-		long *child;
+		kson_ptr_t *child;
 		char *str;
 	} v;
 } kson_node_t;
 
 typedef struct {
 	long n_nodes;
-	kson_node_t *nodes;
+	kson_node_t *nodes; // nodes[0] is the root
 } kson_t;
 
 #define kson_is_internal(p) ((p)->type == KSON_TYPE_BRACKET || (p)->type == KSON_TYPE_BRACE)
@@ -47,28 +54,28 @@ extern "C" {
 	/** Destroy a kson_t object */
 	void kson_destroy(kson_t *kson);
 
-	const kson_node_t *kson_query(const kson_t *kson, int max_depth, ...);
+	const kson_node_t *kson_query(const kson_node_t *root, int max_depth, ...);
 
-	void kson_format(const kson_t *kson);
+	void kson_format(const kson_node_t *root);
 
 #ifdef __cplusplus
 }
 #endif
 
-static inline const kson_node_t *kson_by_key(const kson_node_t *nodes, const kson_node_t *p, const char *key)
+static inline const kson_node_t *kson_by_key(const kson_node_t *p, const char *key)
 {
 	long i;
 	for (i = 0; i < (long)p->n; ++i) {
-		const kson_node_t *q = &nodes[p->v.child[i]];
+		const kson_node_t *q = p->v.child[i].p;
 		if (q->key && strcmp(q->key, key) == 0)
 			return q;
 	}
 	return 0;
 }
 
-static inline const kson_node_t *kson_by_index(const kson_node_t *nodes, const kson_node_t *p, long i)
+static inline const kson_node_t *kson_by_index(const kson_node_t *p, long i)
 {
-	return 0 <= i && i < (long)p->n? &nodes[p->v.child[i]] : 0;
+	return 0 <= i && i < (long)p->n? p->v.child[i].p : 0;
 }
 
 #endif