CharlesKWON
93cf5c8bfa
Foundation for the upcoming PostgreSQL-wire server. The SQL engine
previously held transaction state and the plan cache in module-level
STATICs:
TSqlTxn.prg:16-18
STATIC s_aTxnLog := {}
STATIC s_lInTxn := .F.
STATIC s_hSavepoints := NIL
TFiveSQL.prg:37
STATIC s_hPlanCache := { => }
gengo emits PRG STATIC as Go *package* variables, so two clients
sharing one process serialised through a single transaction log:
client A's `BEGIN; INSERT;` followed by client B's `ROLLBACK`
would silently undo A's insert. Acceptable for embedded single-
caller use; show-stopper for a multi-connection daemon.
Moved each of those into instance fields on a new TSqlSession class.
Every executor instance now carries an oSession pointer that's
inherited by nested subquery executors. A process-default session
is lazy-initialised by SqlDefaultSession() so embedded
`five_SQL(cSQL)` callers (today's only consumer) keep working
unchanged.
Changes
-------
* `_FiveSql2/src/TSqlSession.prg` (new) — class holding the four
ex-STATICs plus seats for auth/ACL state and a list of workareas
the session opened (used later for disconnect cleanup). Module-
level `SqlDefaultSession()` lazily creates one process-wide
default for embedded callers.
* `_FiveSql2/src/TSqlTxn.prg` — added `oSession` DATA; New() takes
an optional oSession and falls back to the default. All STATIC
reads/writes rewritten as `::oSession:aTxnLog`,
`::oSession:lInTxn`, etc.
* `_FiveSql2/src/TFiveSQL.prg` — added `oSession` DATA; New() takes
an optional second arg. Plan-cache reads/writes route through
`::oSession:hPlanCache`. SQL_PLAN_CACHE_MAX now caps each session
independently (a chatty client only flushes its own cache, not
the shared one).
* `_FiveSql2/src/TSqlExecutor.prg` — added `oSession` DATA; New()
takes an optional third arg; `::oTxn := TSqlTxn():New(::oSession)`
propagates the binding. Every in-class `TSqlExecutor():New(...)`
call site for subqueries / UNION / IN-list materialisation /
EXISTS / lifted subqueries now passes `::oSession` through, so a
child executor inherits the parent's session. Standalone helper
functions (SqlEvalExprNode / SqlFetchRowArr / SqlJoinRecurse /
SqlMaterializeSubquery) intentionally fall back to the default
session — they don't BEGIN/COMMIT and the plan cache is keyed by
schema-version anyway.
* `_FiveSql2/src/FiveSqlCls.prg` — `five_SQL()` gains an optional
fourth arg `oSession`. Existing 1-/2-/3-arg callers keep working;
pgserver will create one TSqlSession per connection and pass it.
Verification
------------
Per-session isolation pinned by a fresh PRG-level regression
(reproducer not committed yet — will land with pgserver test
suite). The scenario:
oSessA := TSqlSession():New()
oSessB := TSqlSession():New()
oSqlA := TFiveSQL():New(NIL, oSessA)
oSqlB := TFiveSQL():New(NIL, oSessB)
oSqlA:Execute("BEGIN") -- A in txn
oSqlB:Execute("BEGIN") -- B in txn, A unaffected
oSqlB:Execute("INSERT ... VALUES(2,'b-row')")
oSqlB:Execute("COMMIT") -- B committed, A still in txn
oSqlA:Execute("ROLLBACK") -- A's empty rollback, B's row survives
All four assertions pass post-refactor, would fail pre-refactor
because both sessions wrote the same `s_aTxnLog`.
All six release gates green:
go test ./... ✓
FiveSql2 SQL:1999 43/43 ✓
Harbour compat 56/56 ✓
std.ch 17/17 ✓
FRB 7/7 ✓
examples 65/71 ✓ (unchanged baseline)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
52 lines
1.9 KiB
Plaintext
52 lines
1.9 KiB
Plaintext
/*
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* FiveSqlCls.prg — Public API wrapper: five_SQL() function
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*
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* FiveSql2 — SQL Engine for Harbour DBF/NTX
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*
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* Copyright (c) 2025-2026 Charles KWON (Charles KWON OhJun)
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* Email: charleskwonohjun@gmail.com
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*
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* All rights reserved.
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*/
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#include "FiveSqlDef.ch"
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/*
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* five_SQL( cSQL [, aParams ] [, bBlock ] [, oSession ] ) --> aResult | NIL
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*
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* Execute a SQL statement against the current DBF workareas.
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*
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* Two return modes:
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* 1. Without bBlock: returns { aFieldNames, aRows } on success,
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* or { {"__error__"}, {{nCode, cMsg, cSQL}} } on failure.
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* 2. With bBlock: streams matching rows into the block, spreading
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* the SELECT list as positional params. Returns NIL.
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* Block mode is the high-performance path — no
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* intermediate row array is built.
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*
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* Block mode only fires for simple SELECT queries that the fast path
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* already supports (single table, no JOIN, no GROUP BY, no aggregates,
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* all projections are plain column refs). Complex queries fall back to
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* array mode even when a block is supplied, and the block is invoked
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* once per row after the fact as a compatibility layer.
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*
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* Session parameter:
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* When oSession is NIL (the common embedded case), the engine uses
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* a lazy process-default session via SqlDefaultSession() so existing
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* callers keep working unchanged. The pgserver frontend passes a
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* fresh TSqlSession instance per connection so concurrent clients
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* don't share transaction logs or plan caches.
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*
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* Accepts both parameter positions so existing callers still work:
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* five_SQL( cSQL )
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* five_SQL( cSQL, aParams )
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* five_SQL( cSQL, aParams, bBlock )
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* five_SQL( cSQL, NIL, bBlock )
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* five_SQL( cSQL, NIL, NIL, oSession )
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*/
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FUNCTION five_SQL( cSQL, aParams, bBlock, oSession )
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LOCAL oSql := TFiveSQL():New( aParams, oSession )
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RETURN oSql:Execute( cSQL, bBlock )
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