From 87f871aae392279b9475ea74ffe3bb9149e02e7c Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 19 Jun 2012 12:43:08 +0930
Subject: ntdb: add NTDB_ATTRIBUTE_HASHSIZE

Since we've given up on expansion, let them frob the hashsize again.
We have attributes, so we should use them for optional stuff like
this.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 lib/ntdb/open.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

(limited to 'lib/ntdb/open.c')

diff --git a/lib/ntdb/open.c b/lib/ntdb/open.c
index 4b8c45298b..9de9e9b48c 100644
--- a/lib/ntdb/open.c
+++ b/lib/ntdb/open.c
@@ -273,6 +273,7 @@ _PUBLIC_ enum NTDB_ERROR ntdb_set_attribute(struct ntdb_context *ntdb,
 	case NTDB_ATTRIBUTE_HASH:
 	case NTDB_ATTRIBUTE_SEED:
 	case NTDB_ATTRIBUTE_OPENHOOK:
+	case NTDB_ATTRIBUTE_HASHSIZE:
 		return ntdb_logerr(ntdb, NTDB_ERR_EINVAL,
 				   NTDB_LOG_USE_ERROR,
 				   "ntdb_set_attribute:"
@@ -281,7 +282,9 @@ _PUBLIC_ enum NTDB_ERROR ntdb_set_attribute(struct ntdb_context *ntdb,
 				   ? "NTDB_ATTRIBUTE_HASH"
 				   : attr->base.attr == NTDB_ATTRIBUTE_SEED
 				   ? "NTDB_ATTRIBUTE_SEED"
-				   : "NTDB_ATTRIBUTE_OPENHOOK");
+				   : attr->base.attr == NTDB_ATTRIBUTE_OPENHOOK
+				   ? "NTDB_ATTRIBUTE_OPENHOOK"
+				   : "NTDB_ATTRIBUTE_HASHSIZE");
 	case NTDB_ATTRIBUTE_STATS:
 		return ntdb_logerr(ntdb, NTDB_ERR_EINVAL,
 				   NTDB_LOG_USE_ERROR,
@@ -349,6 +352,9 @@ _PUBLIC_ enum NTDB_ERROR ntdb_get_attribute(struct ntdb_context *ntdb,
 		attr->alloc.free = ntdb->free_fn;
 		attr->alloc.priv_data = ntdb->alloc_data;
 		break;
+	case NTDB_ATTRIBUTE_HASHSIZE:
+		attr->hashsize.size = 1 << ntdb->hash_bits;
+		break;
 	default:
 		return ntdb_logerr(ntdb, NTDB_ERR_EINVAL,
 				   NTDB_LOG_USE_ERROR,
@@ -475,6 +481,15 @@ static struct ntdb_context *alloc_ntdb(const union ntdb_attribute *attr,
 	return default_alloc(NULL, len, NULL);
 }
 
+static unsigned int next_pow2(uint64_t size)
+{
+	unsigned int bits = 1;
+
+	while ((1ULL << bits) < size)
+		bits++;
+	return bits;
+}
+
 _PUBLIC_ struct ntdb_context *ntdb_open(const char *name, int ntdb_flags,
 					int open_flags, mode_t mode,
 					union ntdb_attribute *attr)
@@ -528,6 +543,17 @@ _PUBLIC_ struct ntdb_context *ntdb_open(const char *name, int ntdb_flags,
 			ntdb->openhook = attr->openhook.fn;
 			ntdb->openhook_data = attr->openhook.data;
 			break;
+		case NTDB_ATTRIBUTE_HASHSIZE:
+			ntdb->hash_bits = next_pow2(attr->hashsize.size);
+			if (ntdb->hash_bits > 31) {
+				ecode = ntdb_logerr(ntdb, NTDB_ERR_EINVAL,
+						    NTDB_LOG_USE_ERROR,
+						    "ntdb_open: hash_size %u"
+						    " too large",
+						    attr->hashsize.size);
+				goto fail;
+			}
+			break;
 		default:
 			/* These are set as normal. */
 			ecode = ntdb_set_attribute(ntdb, attr);
-- 
cgit