From f7d8812e6cdaf265ebb20a0f2e25536d431264ab Mon Sep 17 00:00:00 2001
From: Leo Yuriev <leo@yuriev.ru>
Date: Wed, 2 Sep 2015 17:53:48 +0300
Subject: [PATCH] lmdb: n-entries info from b-tree traversal in mdb_chk.

Change-Id: Ic9343dcdba976ac51c8f5776d2f7c9fed59da8e0
---
 lmdb.h    |  2 +-
 mdb.c     | 12 ++++++------
 mdb_chk.c |  7 ++++---
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/lmdb.h b/lmdb.h
index e451f29e..74ab55b2 100644
--- a/lmdb.h
+++ b/lmdb.h
@@ -1659,7 +1659,7 @@ typedef void MDB_debug_func(int type, const char *function, int line,
 int mdb_setup_debug(int flags, MDB_debug_func* logger, long edge_txn);
 
 typedef int MDB_pgvisitor_func(size_t pgno, unsigned pgnumber, void* ctx,
-					const char* dbi, const char *type,
+					const char* dbi, const char *type, int nentries,
 					int payload_bytes, int header_bytes, int unused_bytes);
 int mdb_env_pgwalk(MDB_txn *txn, MDB_pgvisitor_func* visitor, void* ctx);
 
diff --git a/mdb.c b/mdb.c
index c6e7aa06..fa864723 100644
--- a/mdb.c
+++ b/mdb.c
@@ -9895,8 +9895,8 @@ mdb_env_walk(mdb_walk_ctx_t *ctx, const char* dbi, pgno_t pg, int flags, int dee
 			over_unused = omp->mp_pages * ctx->mw_txn->mt_env->me_psize
 					- over_payload - over_header;
 
-			rc = ctx->mw_visitor(*opg, omp->mp_pages, ctx->mw_user, dbi, "overflow-data",
-					over_payload, over_header, over_unused);
+			rc = ctx->mw_visitor(*opg, omp->mp_pages, ctx->mw_user, dbi,
+					"overflow-data", 1, over_payload, over_header, over_unused);
 			if (rc)
 				return rc;
 			continue;
@@ -9922,8 +9922,8 @@ mdb_env_walk(mdb_walk_ctx_t *ctx, const char* dbi, pgno_t pg, int flags, int dee
 		}
 	}
 
-	return ctx->mw_visitor(mp->mp_p.p_pgno, 1, ctx->mw_user, dbi,
-		type, payload_size, header_size, unused_size + align_bytes);
+	return ctx->mw_visitor(mp->mp_p.p_pgno, 1, ctx->mw_user, dbi, type,
+		nkeys, payload_size, header_size, unused_size + align_bytes);
 }
 
 int ESECT
@@ -9936,14 +9936,14 @@ mdb_env_pgwalk(MDB_txn *txn, MDB_pgvisitor_func* visitor, void* user)
 	ctx.mw_user = user;
 	ctx.mw_visitor = visitor;
 
-	rc = visitor(0, 2, user, "lmdb", "meta", sizeof(MDB_meta)*2, PAGEHDRSZ*2,
+	rc = visitor(0, 2, user, "lmdb", "meta", 2, sizeof(MDB_meta)*2, PAGEHDRSZ*2,
 				 (txn->mt_env->me_psize - sizeof(MDB_meta) - PAGEHDRSZ) *2);
 	if (! rc && txn->mt_dbs[FREE_DBI].md_root != P_INVALID)
 		rc = mdb_env_walk(&ctx, "free", txn->mt_dbs[FREE_DBI].md_root, 0, 0);
 	if (! rc && txn->mt_dbs[MAIN_DBI].md_root != P_INVALID)
 		rc = mdb_env_walk(&ctx, "main", txn->mt_dbs[MAIN_DBI].md_root, 0, 0);
 	if (! rc)
-		rc = visitor(P_INVALID, 0, user, NULL, NULL, -1, 0, 0);
+		rc = visitor(P_INVALID, 0, user, NULL, NULL, 0, 0, 0, 0);
 	return rc;
 }
 
diff --git a/mdb_chk.c b/mdb_chk.c
index 982178d8..5ef27faa 100644
--- a/mdb_chk.c
+++ b/mdb_chk.c
@@ -211,7 +211,7 @@ static size_t problems_pop(struct problem* list) {
 }
 
 static int pgvisitor(size_t pgno, unsigned pgnumber, void* ctx, const char* dbi,
-	const char* type, int payload_bytes, int header_bytes, int unused_bytes)
+	const char* type, int nentries, int payload_bytes, int header_bytes, int unused_bytes)
 {
 	if (type) {
 		size_t page_bytes = payload_bytes + header_bytes + unused_bytes;
@@ -236,8 +236,9 @@ static int pgvisitor(size_t pgno, unsigned pgnumber, void* ctx, const char* dbi,
 		if (header_bytes < sizeof(long) || header_bytes >= stat.ms_psize - sizeof(long))
 			problem_add(pgno, "illegal header-length", "%zu < %i < %zu",
 				sizeof(long), header_bytes, stat.ms_psize - sizeof(long));
-		else if (payload_bytes < 1) {
-			problem_add(pgno, "empty page", "payload %i bytes", payload_bytes);
+		if (payload_bytes < 1 || nentries < 1) {
+			problem_add(pgno, "empty page", "payload %i bytes, %i entries",
+						payload_bytes, nentries);
 			walk.dbi_empty_pages[index] += 1;
 		}