From 54b1960d18042cf6dfd86cfe01d58455357586d2 Mon Sep 17 00:00:00 2001
From: Daniel Silverstone <dsilvers@digital-scurf.org>
Date: Sun, 23 Feb 2020 16:46:22 +0000
Subject: utils: Add iteration API to hashmap

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>
---
 utils/hashmap.c | 19 +++++++++++++++++++
 utils/hashmap.h | 22 ++++++++++++++++++++++
 2 files changed, 41 insertions(+)

(limited to 'utils')

diff --git a/utils/hashmap.c b/utils/hashmap.c
index 7ed19946b..bfbf6ceb8 100644
--- a/utils/hashmap.c
+++ b/utils/hashmap.c
@@ -213,3 +213,22 @@ hashmap_remove(hashmap_t *hashmap, void *key)
 
 	return false;
 }
+
+/* Exported function, documented in hashmap.h */
+bool
+hashmap_iterate(hashmap_t *hashmap, hashmap_iteration_cb_t cb, void *ctx)
+{
+	for (uint32_t bucket = 0;
+	     bucket < hashmap->bucket_count;
+	     bucket++) {
+		for (hashmap_entry_t *entry = hashmap->buckets[bucket];
+		     entry != NULL;
+		     entry = entry->next) {
+			/* If the callback returns true, we early-exit */
+			if (cb(entry->key, entry->value, ctx))
+				return true;
+		}
+	}
+
+	return false;
+}
diff --git a/utils/hashmap.h b/utils/hashmap.h
index 462b51ed2..cb8fd5074 100644
--- a/utils/hashmap.h
+++ b/utils/hashmap.h
@@ -61,6 +61,16 @@ typedef void* (*hashmap_value_alloc_t)(void *);
  */
 typedef void (*hashmap_value_destroy_t)(void *);
 
+/**
+ * Hashmap iteration callback function type.
+ *
+ * First parameter is the key, second is the value.
+ * The final parameter is the context pointer for the iteration.
+ *
+ * Return true to stop iterating early
+ */
+typedef bool (*hashmap_iteration_cb_t)(void *, void *, void *);
+
 /**
  * Parameters for hashmaps
  */
@@ -163,5 +173,17 @@ void *hashmap_insert(hashmap_t *hashmap, void *key);
  */
 bool hashmap_remove(hashmap_t *hashmap, void *key);
 
+/**
+ * Iterate the hashmap
+ *
+ * For each key/value pair in the hashmap, call the callback passing in
+ * the key and value.  During iteration you MUST NOT mutate the hashmap.
+ *
+ * \param hashmap The hashmap to iterate
+ * \param cb The callback for each key,value pair
+ * \param ctx The callback context
+ * \return Whether or not we stopped iteration early
+ */
+bool hashmap_iterate(hashmap_t *hashmap, hashmap_iteration_cb_t cb, void *ctx);
 
 #endif
-- 
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