`with-transaction` problem at datalevin.binding.cpp.CppLMDB/list_count

[aldebogdanov]

I encountered an interesting bug.

This code:

(ns dtlv-transaction-error.core)

(comment
  (require '[datalevin.core :as d])

  (def schema {:user/username {:db/valueType :db.type/string
                               :db/cardinality :db.cardinality/one
                               :db/unique :db.unique/identity}

               :group/id {:db/valueType :db.type/uuid
                          :db/cardinality :db.cardinality/one
                          :db/unique :db.unique/identity}

               :group/users {:db/valueType :db.type/ref
                             :db/cardinality :db.cardinality/many}

               :rule/group {:db/valueType :db.type/ref
                            :db/cardinality :db.cardinality/one}

               :rule/permission {:db/valueType :db.type/keyword
                                 :db/cardinality :db.cardinality/one}

               :rule/group+permission {:db/valueType :db.type/tuple
                                       :db/cardinality :db.cardinality/one
                                       :db/tupleAttrs [:rule/group :rule/permission]
                                       :db/unique :db.unique/identity}})

  (def cn (d/get-conn "./dtlv" schema {:validate-data? true
                                       :closed-schema? true
                                       :kv-opts {:max-readers 512}}))

  (def init-tx [{:db/id -1
                 :user/username "sasha"}
                {:db/id -2
                 :group/id (random-uuid)
                 :group/users [-1]}
                {:rule/group -2
                 :rule/permission :permission/manager}])

  (d/transact! cn init-tx)

  (d/q '[:find ?g . :in $ ?username
         :where
         [?u :user/username ?username]
         [?g :group/users ?u]
         [?r :rule/group ?g]
         [?r :rule/permission :permission/manager]] (d/db cn) "sasha")

  (d/with-transaction [c cn]
    (d/q '[:find ?g . :in $ ?username
           :where
           [?u :user/username ?username]
           [?g :group/users ?u]
           [?r :rule/group ?g]
           [?r :rule/permission :permission/manager]] (d/db c) "sasha"))
)

Step by step running expressions in comment block. Everything is fine until the last expression that is d/with-transaction. Plain query returns correct 2, but query in transaction fails with:

clj꞉dtlv-transaction-error.core꞉> 
; Execution error (ExceptionInfo) at datalevin.binding.cpp.CppLMDB/list_count (cpp.clj:987).
; Fail to count list: #error {
;  :cause "Key cannot be larger than 511 bytes."
;  :data {:input #datalevin/Indexable [0 5 2 -8 "" 0]}
;  :via
;  [{:type clojure.lang.ExceptionInfo
;    :message "Key cannot be larger than 511 bytes."
;    :data {:input #datalevin/Indexable [0 5 2 -8 "" 0]}
;    :at [datalevin.binding.cpp.Rtx put_key "cpp.clj" 142]}]
;  :trace
;  [[datalevin.binding.cpp.Rtx put_key "cpp.clj" 142]
;   [datalevin.binding.cpp$list_count_STAR_ invokeStatic "cpp.clj" 471]
;   [datalevin.binding.cpp$list_count_STAR_ invoke "cpp.clj" 469]
;   [datalevin.binding.cpp.CppLMDB list_count "cpp.clj" 986]
;   [datalevin.storage.Store av_size "storage.clj" 862]
;   [datalevin.query$count_init_follows$fn__29126 invoke "query.clj" 1760]
;   [clojure.core.reducers$map$fn__12396$fn__12397 invoke "reducers.clj" 134]
;   [clojure.core.protocols$iterator_reduce_BANG_ invokeStatic "protocols.clj" 42]
;   [clojure.core.protocols$iter_reduce invokeStatic "protocol
; s.clj" 52]
;   [clojure.core.protocols$fn__8256 invokeStatic "protocols.clj" 74]
;   [clojure.core.protocols$fn__8256 invoke "protocols.clj" 74]
;   [clojure.core.protocols$fn__8203$G__8198__8216 invoke "protocols.clj" 13]
;   [clojure.core.reducers$reduce invokeStatic "reducers.clj" 46]
;   [clojure.core.reducers$fn__12475 invokeStatic "reducers.clj" 324]
;   [clojure.core.reducers$fn__12475 invoke "reducers.clj" 314]
;   [clojure.core.reducers$fn__12358$G__12353__12369 invoke "reducers.clj" 48]
;   [clojure.core.reducers$folder$reify__12379 coll_fold "reducers.clj" 97]
;   [clojure.core.reducers$fold invokeStatic "reducers.clj" 65]
;   [clojure.core.reducers$fold invoke "reducers.clj" 51]
;   [clojure.core.reducers$fold invokeStatic "reducers.clj" 63]
;   [clojure.core.reducers$fold invoke "reducers.clj" 51]
;   [clojure.core.reducers$fold invokeStatic "reducers.clj" 62]
;   [clojure.core.reducers$fold invoke "reducers.clj" 51]
;   [datalevin.query$count_init_follows invokeStatic "query.clj" 1758]
;   [datalevin.query$count_init_follows i
; nvoke "query.clj" 1754]
;   [datalevin.query$estimate_link_size invokeStatic "query.clj" 1779]
;   [datalevin.query$estimate_link_size invoke "query.clj" 1763]
;   [datalevin.query$estimate_join_size invokeStatic "query.clj" 1792]
;   [datalevin.query$estimate_join_size invoke "query.clj" 1787]
;   [datalevin.query$binary_plan_STAR_ invokeStatic "query.clj" 1829]
;   [datalevin.query$binary_plan_STAR_ invoke "query.clj" 1825]
;   [datalevin.query$binary_plan$fn__29148 invoke "query.clj" 1839]
;   [clojure.core$map$fn__5950$fn__5951 invoke "core.clj" 2759]
;   [clojure.core$filter$fn__5977$fn__5978 invoke "core.clj" 2823]
;   [clojure.lang.PersistentVector reduce "PersistentVector.java" 418]
;   [clojure.core$transduce invokeStatic "core.clj" 7025]
;   [clojure.core$into invokeStatic "core.clj" 7042]
;   [clojure.core$into invoke "core.clj" 7029]
;   [datalevin.query$binary_plan invokeStatic "query.clj" 1836]
;   [datalevin.query$binary_plan invoke "query.clj" 1833]
;   [datalevin.query$plans$fn__29154$fn__29159 invoke "query.clj" 1858]
;   [c
; lojure.core.protocols$iterator_reduce_BANG_ invokeStatic "protocols.clj" 42]
;   [clojure.core.protocols$iter_reduce invokeStatic "protocols.clj" 52]
;   [clojure.core.protocols$fn__8256 invokeStatic "protocols.clj" 74]
;   [clojure.core.protocols$fn__8256 invoke "protocols.clj" 74]
;   [clojure.core.protocols$fn__8203$G__8198__8216 invoke "protocols.clj" 13]
;   [clojure.core$reduce invokeStatic "core.clj" 6965]
;   [clojure.core$reduce invoke "core.clj" 6947]
;   [datalevin.query$plans$fn__29154 invoke "query.clj" 1852]
;   [datalevin.util$map_PLUS_$fn__14723$fn__14724 invoke "util.clj" 631]
;   [clojure.lang.AFn call "AFn.java" 18]
;   [java.util.concurrent.FutureTask run "FutureTask.java" 317]
;   [java.util.concurrent.ThreadPoolExecutor runWorker "ThreadPoolExecutor.java" 1144]
;   [java.util.concurrent.ThreadPoolExecutor$Worker run "ThreadPoolExecutor.java" 642]
;   [java.lang.Thread run "Thread.java" 1583]]}

deps.edn:

{:paths ["src" "resources"]
 :deps {org.clojure/clojure {:mvn/version "1.12.0"}
        datalevin/datalevin {:mvn/version "0.9.22"}}
 :aliases
 {:run
  {:main-opts ["-m" "dtlv-transaction-error.core"]}
  :build
  {:deps {io.github.clojure/tools.build {:mvn/version "0.10.5"}}
   :ns-default build}}}

Environment:

mbpm2-avbo % ~/dev/dtlv-transaction-error 
▸ uname -a
Darwin mbpm2-avbo.local 24.5.0 Darwin Kernel Version 24.5.0: Tue Apr 22 19:54:25 PDT 2025; root:xnu-11417.121.6~2/RELEASE_ARM64_T6020 arm64

mbpm2-avbo % ~/dev/dtlv-transaction-error 
▸ java -version
openjdk version "21.0.6" 2025-01-21 LTS
OpenJDK Runtime Environment Temurin-21.0.6+7 (build 21.0.6+7-LTS)
OpenJDK 64-Bit Server VM Temurin-21.0.6+7 (build 21.0.6+7-LTS, mixed mode, sharing)

mbpm2-avbo % ~/dev/dtlv-transaction-error 
▸ clj --version
Clojure CLI version 1.12.0.1517