From 1aea9f44924814e50a4bcc090e22a7533eb5f5f3 Mon Sep 17 00:00:00 2001
From: hyung-hwan <hyunghwan.chung@gmail.com>
Date: Fri, 1 Mar 2019 09:27:03 +0000
Subject: [PATCH] some use of sdbm hash

---
 qse/lib/awk/val.c |  7 +++++++
 qse/lib/cmn/htb.c | 21 +++++++++++----------
 qse/lib/cmn/htl.c |  6 +++---
 qse/lib/cmn/oht.c | 20 +++++++++++++-------
 4 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/qse/lib/awk/val.c b/qse/lib/awk/val.c
index 8db2a86c..022c9b2a 100644
--- a/qse/lib/awk/val.c
+++ b/qse/lib/awk/val.c
@@ -1698,9 +1698,16 @@ int qse_awk_rtx_strtonum (
 
 static qse_awk_uint_t hash (qse_uint8_t* ptr, qse_size_t len)
 {
+	/*
 	qse_awk_uint_t h = 5381;
 	while (len > 0) h = ((h << 5) + h) + ptr[--len];
 	return h;
+	*/
+
+	/* SDBM hash */
+	qse_awk_uint_t h = 0;
+	while (len > 0) h = (h << 6) + (h << 16) - h + ptr[--len];
+	return h;
 }
 
 qse_awk_int_t qse_awk_rtx_hashval (qse_awk_rtx_t* rtx, qse_awk_val_t* v)
diff --git a/qse/lib/cmn/htb.c b/qse/lib/cmn/htb.c
index 3cf122bf..4fb3e86a 100644
--- a/qse/lib/cmn/htb.c
+++ b/qse/lib/cmn/htb.c
@@ -672,7 +672,6 @@ void qse_htb_clear (htb_t* htb)
 	}
 }
 
-
 void qse_htb_walk (htb_t* htb, walker_t walker, void* ctx)
 {
 	size_t i;
@@ -734,29 +733,31 @@ pair_t* qse_htb_getnextpair (htb_t* htb, pair_t* pair, size_t* buckno)
 	return QSE_NULL;
 }
 
-size_t qse_htb_dflhash (
-	const htb_t* htb, const void* kptr, size_t klen)
+size_t qse_htb_dflhash (const htb_t* htb, const void* kptr, size_t klen)
 {
+	const byte_t* p = (const byte_t*)kptr;
+	const byte_t* bound = p + klen;
+#if 0
 	/*size_t h = 2166136261;*/
 	/*size_t h = 0;*/
 	size_t h = 5381;
-	const byte_t* p = (const byte_t*)kptr;
-	const byte_t* bound = p + klen;
 
 	while (p < bound)
 	{
 		/*h = (h * 16777619) ^ *p++;*/
 		/*h = h * 31 + *p++;*/
 		h = ((h << 5) + h) + *p++;
-	}	
+	}
+#else
+	/* SDBM hash */
+	size_t h = 0;
+	while (p < bound) h = (h << 6) + (h << 16) - h + *p++;
+#endif
 
 	return h ; 
 }
 
-int qse_htb_dflcomp (
-	const htb_t* htb, 
-	const void* kptr1, size_t klen1, 
-	const void* kptr2, size_t klen2)
+int qse_htb_dflcomp (const htb_t* htb, const void* kptr1, size_t klen1, const void* kptr2, size_t klen2)
 {
 	if (klen1 == klen2) return QSE_MEMCMP (kptr1, kptr2, KTOB(htb,klen1));
 	/* it just returns 1 to indicate that they are different. */
diff --git a/qse/lib/cmn/htl.c b/qse/lib/cmn/htl.c
index a823503f..d915d894 100644
--- a/qse/lib/cmn/htl.c
+++ b/qse/lib/cmn/htl.c
@@ -843,7 +843,7 @@ QSE_INLINE qse_uint32_t qse_genhash32_update (const void* data, qse_size_t size,
 
 qse_uint32_t qse_genhash32 (const void *data, qse_size_t size)
 {
-	return qse_genhash32_update (data, size, FNV_MAGIC_INIT);
+	return qse_genhash32_update(data, size, FNV_MAGIC_INIT);
 }
 
 /*
@@ -855,7 +855,7 @@ qse_uint32_t qse_mbshash32 (const qse_mchar_t* p)
 
 	while (*p) 
 	{
-		hash ^= (qse_uint32_t) (*p++);
+		hash ^= (qse_uint32_t)(*p++);
 		hash *= FNV_MAGIC_PRIME;
 	}
 
@@ -873,7 +873,7 @@ qse_uint32_t qse_wcshash32 (const qse_wchar_t* p)
 		hash ^= (qse_uint32_t)(*p);
 		hash *= FNV_MAGIC_PRIME;
 	#else
-		hash = qse_genhash_update (*p, QSE_SIZEOF(*p), hash);
+		hash = qse_genhash_update(*p, QSE_SIZEOF(*p), hash);
 	#endif
 		p++;
 	}
diff --git a/qse/lib/cmn/oht.c b/qse/lib/cmn/oht.c
index e0bd8830..ff9b6494 100644
--- a/qse/lib/cmn/oht.c
+++ b/qse/lib/cmn/oht.c
@@ -4,24 +4,30 @@
 #define DATA_PTR(oht,index) \
 	((void*)(((qse_byte_t*)(oht)->data) + ((index) * (oht)->scale)))
 
-static QSE_INLINE_ALWAYS qse_size_t default_hasher (
-	qse_oht_t* oht, const void* data)
+static QSE_INLINE_ALWAYS qse_size_t default_hasher (qse_oht_t* oht, const void* data)
 {
-	qse_size_t h = 5381;
 	const qse_byte_t* p = (const qse_byte_t*)data;
 	const qse_byte_t* bound = p + oht->scale;
+
+#if 0
+	// DJB2 hash
+	qse_size_t h = 5381;
 	while (p < bound) h = ((h << 5) + h) + *p++;
+#else
+	// SDBM hash
+	qse_size_t h = 0;
+	while (p < bound) h = (h << 6) + (h << 16) - h + *p++;
+#endif
+
 	return h ; 
 }
 
-static QSE_INLINE_ALWAYS int default_comper (
-	qse_oht_t* oht, const void* data1, const void* data2)
+static QSE_INLINE_ALWAYS int default_comper (qse_oht_t* oht, const void* data1, const void* data2)
 {
 	return QSE_MEMCMP(data1, data2, oht->scale);
 }
 
-static QSE_INLINE_ALWAYS void default_copier (
-	qse_oht_t* oht, void* dst, const void* src)
+static QSE_INLINE_ALWAYS void default_copier (qse_oht_t* oht, void* dst, const void* src)
 {
 	QSE_MEMCPY (dst, src, oht->scale);
 }