From 9d007e481048296f09f59bd19bb7ae584563cd95 Mon Sep 17 00:00:00 2001
From: Suryandaru Triandana <syndtr@gmail.com>
Date: Fri, 22 Feb 2019 12:17:00 +0700
Subject: [PATCH] docs: add warning regarding iterator buffer usage (fixes
 #258)

---
 leveldb/db.go             | 4 ++++
 leveldb/db_snapshot.go    | 4 ++++
 leveldb/db_transaction.go | 4 ++++
 leveldb/memdb/memdb.go    | 4 ++++
 leveldb/table/reader.go   | 4 ++++
 5 files changed, 20 insertions(+)

diff --git a/leveldb/db.go b/leveldb/db.go
index b27c38d3..90fedf7b 100644
--- a/leveldb/db.go
+++ b/leveldb/db.go
@@ -872,6 +872,10 @@ func (db *DB) Has(key []byte, ro *opt.ReadOptions) (ret bool, err error) {
 // DB. And a nil Range.Limit is treated as a key after all keys in
 // the DB.
 //
+// WARNING: Any slice returned by interator (e.g. slice returned by calling
+// Iterator.Key() or Iterator.Key() methods), its content should not be modified
+// unless noted otherwise.
+//
 // The iterator must be released after use, by calling Release method.
 //
 // Also read Iterator documentation of the leveldb/iterator package.
diff --git a/leveldb/db_snapshot.go b/leveldb/db_snapshot.go
index 2c69d2e5..c2ad70c8 100644
--- a/leveldb/db_snapshot.go
+++ b/leveldb/db_snapshot.go
@@ -142,6 +142,10 @@ func (snap *Snapshot) Has(key []byte, ro *opt.ReadOptions) (ret bool, err error)
 // DB. And a nil Range.Limit is treated as a key after all keys in
 // the DB.
 //
+// WARNING: Any slice returned by interator (e.g. slice returned by calling
+// Iterator.Key() or Iterator.Value() methods), its content should not be
+// modified unless noted otherwise.
+//
 // The iterator must be released after use, by calling Release method.
 // Releasing the snapshot doesn't mean releasing the iterator too, the
 // iterator would be still valid until released.
diff --git a/leveldb/db_transaction.go b/leveldb/db_transaction.go
index b8f7e7d2..1a000018 100644
--- a/leveldb/db_transaction.go
+++ b/leveldb/db_transaction.go
@@ -69,6 +69,10 @@ func (tr *Transaction) Has(key []byte, ro *opt.ReadOptions) (bool, error) {
 // DB. And a nil Range.Limit is treated as a key after all keys in
 // the DB.
 //
+// WARNING: Any slice returned by interator (e.g. slice returned by calling
+// Iterator.Key() or Iterator.Key() methods), its content should not be modified
+// unless noted otherwise.
+//
 // The iterator must be released after use, by calling Release method.
 //
 // Also read Iterator documentation of the leveldb/iterator package.
diff --git a/leveldb/memdb/memdb.go b/leveldb/memdb/memdb.go
index b661c08a..824e47f5 100644
--- a/leveldb/memdb/memdb.go
+++ b/leveldb/memdb/memdb.go
@@ -397,6 +397,10 @@ func (p *DB) Find(key []byte) (rkey, value []byte, err error) {
 // DB. And a nil Range.Limit is treated as a key after all keys in
 // the DB.
 //
+// WARNING: Any slice returned by interator (e.g. slice returned by calling
+// Iterator.Key() or Iterator.Key() methods), its content should not be modified
+// unless noted otherwise.
+//
 // The iterator must be released after use, by calling Release method.
 //
 // Also read Iterator documentation of the leveldb/iterator package.
diff --git a/leveldb/table/reader.go b/leveldb/table/reader.go
index 16cfbaa0..496feb6f 100644
--- a/leveldb/table/reader.go
+++ b/leveldb/table/reader.go
@@ -787,6 +787,10 @@ func (r *Reader) getDataIterErr(dataBH blockHandle, slice *util.Range, verifyChe
 // table. And a nil Range.Limit is treated as a key after all keys in
 // the table.
 //
+// WARNING: Any slice returned by interator (e.g. slice returned by calling
+// Iterator.Key() or Iterator.Key() methods), its content should not be modified
+// unless noted otherwise.
+//
 // The returned iterator is not safe for concurrent use and should be released
 // after use.
 //