src/backend/commands/explain.c | 1 + src/backend/nodes/extensible.c | 69 +++++++++++++++++++++++++ src/backend/nodes/outfuncs.c | 6 +-- src/backend/nodes/readfuncs.c | 19 ++----- src/backend/optimizer/plan/createplan.c | 1 + src/include/executor/nodeCustom.h | 1 + src/include/nodes/execnodes.h | 35 +------------ src/include/nodes/extensible.h | 91 ++++++++++++++++++++++++++++++++- src/include/nodes/plannodes.h | 14 +---- src/include/nodes/relation.h | 19 +------ 10 files changed, 174 insertions(+), 82 deletions(-) diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c index 787b0b9..09c2304 100644 --- a/src/backend/commands/explain.c +++ b/src/backend/commands/explain.c @@ -21,6 +21,7 @@ #include "commands/prepare.h" #include "executor/hashjoin.h" #include "foreign/fdwapi.h" +#include "nodes/extensible.h" #include "nodes/nodeFuncs.h" #include "optimizer/clauses.h" #include "optimizer/planmain.h" diff --git a/src/backend/nodes/extensible.c b/src/backend/nodes/extensible.c index 2473b65..2931208 100644 --- a/src/backend/nodes/extensible.c +++ b/src/backend/nodes/extensible.c @@ -23,6 +23,7 @@ #include "nodes/extensible.h" #include "utils/hsearch.h" +/* for registration of extensible node */ static HTAB *extensible_node_methods = NULL; typedef struct @@ -31,6 +32,15 @@ typedef struct const ExtensibleNodeMethods *methods; } ExtensibleNodeEntry; +/* for registration of custom-scan methods */ +static HTAB *custom_scan_methods = NULL; + +typedef struct +{ + char CustomName[CUSTOM_NAME_MAX_LEN]; + const CustomScanMethods *methods; +} CustomScanMethodsEntry; + /* * Register a new type of extensible node. */ @@ -91,3 +101,62 @@ GetExtensibleNodeMethods(const char *extnodename, bool missing_ok) return entry->methods; } + +/* + * Register a new custom scan methods + */ +void +RegisterCustomScanMethods(const CustomScanMethods *methods) +{ + CustomScanMethodsEntry *entry; + bool found; + + if (custom_scan_methods == NULL) + { + HASHCTL ctl; + + memset(&ctl, 0, sizeof(HASHCTL)); + ctl.keysize = CUSTOM_NAME_MAX_LEN; + ctl.entrysize = sizeof(CustomScanMethodsEntry); + custom_scan_methods = hash_create("Custom Scan Methods", + 100, &ctl, HASH_ELEM); + } + + if (strlen(methods->CustomName) >= CUSTOM_NAME_MAX_LEN) + elog(ERROR, "CustomScanMethods name is too long"); + + entry = (CustomScanMethodsEntry *) hash_search(custom_scan_methods, + methods->CustomName, + HASH_ENTER, &found); + if (found) + ereport(ERROR, + (errcode(ERRCODE_DUPLICATE_OBJECT), + errmsg("CustomScanMethods \"%s\" already exists", + methods->CustomName))); + + entry->methods = methods; +} + +/* + * Get the methods for a given name of CustomScanMethods + */ +const CustomScanMethods * +GetCustomScanMethods(const char *CustomName, bool missing_ok) +{ + CustomScanMethodsEntry *entry = NULL; + + if (custom_scan_methods != NULL) + entry = (CustomScanMethodsEntry *) hash_search(custom_scan_methods, + CustomName, + HASH_FIND, NULL); + if (!entry) + { + if (missing_ok) + return NULL; + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("CustomScanMethods \"%s\" was not registered", + CustomName))); + } + return entry->methods; +} diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index 32d03f7..83abaa6 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -632,11 +632,9 @@ _outCustomScan(StringInfo str, const CustomScan *node) WRITE_NODE_FIELD(custom_private); WRITE_NODE_FIELD(custom_scan_tlist); WRITE_BITMAPSET_FIELD(custom_relids); - /* Dump library and symbol name instead of raw pointer */ + /* CustomName is a key to lookup CustomScanMethods */ appendStringInfoString(str, " :methods "); - _outToken(str, node->methods->LibraryName); - appendStringInfoChar(str, ' '); - _outToken(str, node->methods->SymbolName); + _outToken(str, node->methods->CustomName); } static void diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c index 6db0492..cb0752a 100644 --- a/src/backend/nodes/readfuncs.c +++ b/src/backend/nodes/readfuncs.c @@ -1827,8 +1827,7 @@ static CustomScan * _readCustomScan(void) { READ_LOCALS(CustomScan); - char *library_name; - char *symbol_name; + char *custom_name; const CustomScanMethods *methods; ReadCommonScan(&local_node->scan); @@ -1840,19 +1839,11 @@ _readCustomScan(void) READ_NODE_FIELD(custom_scan_tlist); READ_BITMAPSET_FIELD(custom_relids); - /* - * Reconstruction of methods using library and symbol name - */ + /* Lookup CustomScanMethods by CustomName */ token = pg_strtok(&length); /* skip methods: */ - token = pg_strtok(&length); /* LibraryName */ - library_name = nullable_string(token, length); - token = pg_strtok(&length); /* SymbolName */ - symbol_name = nullable_string(token, length); - - methods = (const CustomScanMethods *) - load_external_function(library_name, symbol_name, true, NULL); - Assert(strcmp(methods->LibraryName, library_name) == 0 && - strcmp(methods->SymbolName, symbol_name) == 0); + token = pg_strtok(&length); /* CustomName */ + custom_name = nullable_string(token, length); + methods = GetCustomScanMethods(custom_name, false); local_node->methods = methods; READ_DONE(); diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index d159a17..e4bc14a 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -24,6 +24,7 @@ #include "catalog/pg_class.h" #include "foreign/fdwapi.h" #include "miscadmin.h" +#include "nodes/extensible.h" #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" #include "optimizer/clauses.h" diff --git a/src/include/executor/nodeCustom.h b/src/include/executor/nodeCustom.h index 410a3ad..9d0b393 100644 --- a/src/include/executor/nodeCustom.h +++ b/src/include/executor/nodeCustom.h @@ -14,6 +14,7 @@ #include "access/parallel.h" #include "nodes/execnodes.h" +#include "nodes/extensible.h" /* * General executor code diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 0113e5c..bf2a09b 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -1606,38 +1606,7 @@ typedef struct ForeignScanState * the BeginCustomScan method. * ---------------- */ -struct ParallelContext; /* avoid including parallel.h here */ -struct shm_toc; /* avoid including shm_toc.h here */ -struct ExplainState; /* avoid including explain.h here */ -struct CustomScanState; - -typedef struct CustomExecMethods -{ - const char *CustomName; - - /* Executor methods: mark/restore are optional, the rest are required */ - void (*BeginCustomScan) (struct CustomScanState *node, - EState *estate, - int eflags); - TupleTableSlot *(*ExecCustomScan) (struct CustomScanState *node); - void (*EndCustomScan) (struct CustomScanState *node); - void (*ReScanCustomScan) (struct CustomScanState *node); - void (*MarkPosCustomScan) (struct CustomScanState *node); - void (*RestrPosCustomScan) (struct CustomScanState *node); - /* Optional: parallel execution support */ - Size (*EstimateDSMCustomScan) (struct CustomScanState *node, - struct ParallelContext *pcxt); - void (*InitializeDSMCustomScan) (struct CustomScanState *node, - struct ParallelContext *pcxt, - void *coordinate); - void (*InitializeWorkerCustomScan) (struct CustomScanState *node, - struct shm_toc *toc, - void *coordinate); - /* Optional: print additional information in EXPLAIN */ - void (*ExplainCustomScan) (struct CustomScanState *node, - List *ancestors, - struct ExplainState *es); -} CustomExecMethods; +struct CustomExecMethods; typedef struct CustomScanState { @@ -1645,7 +1614,7 @@ typedef struct CustomScanState uint32 flags; /* mask of CUSTOMPATH_* flags, see relation.h */ List *custom_ps; /* list of child PlanState nodes, if any */ Size pscan_len; /* size of parallel coordination information */ - const CustomExecMethods *methods; + const struct CustomExecMethods *methods; } CustomScanState; /* ---------------------------------------------------------------- diff --git a/src/include/nodes/extensible.h b/src/include/nodes/extensible.h index 96ae7bc..605833f 100644 --- a/src/include/nodes/extensible.h +++ b/src/include/nodes/extensible.h @@ -1,7 +1,7 @@ /*------------------------------------------------------------------------- * * extensible.h - * Definitions for extensible node type + * Definitions for extensible node type and custom-xxx-methods * * * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group @@ -14,7 +14,11 @@ #ifndef EXTENSIBLE_H #define EXTENSIBLE_H -#include "nodes/nodes.h" +#include "access/parallel.h" +#include "commands/explain.h" +#include "nodes/execnodes.h" +#include "nodes/plannodes.h" +#include "nodes/relation.h" #define EXTNODENAME_MAX_LEN 64 @@ -69,4 +73,87 @@ extern void RegisterExtensibleNodeMethods(const ExtensibleNodeMethods *method); extern const ExtensibleNodeMethods *GetExtensibleNodeMethods(const char *name, bool missing_ok); +/* + * Definition of Custom(Path|Scan|Exec)Methods. + * + * The following structures are callback definition for each relavant custom- + * node types. + * Right now, only CustomScan node can be serialized/deserialized using + * nodeToString/stringToNode. So, extension that performs as a custom-scan + * provider has to support reconstruction of 'methods' of CustomScanMethods + * pointer on background worker processes. + * As ExtensibleNode type doing above, extension registers CustomExecMethods + * identified by CustomName preliminary. A serialized CustomScan contains + * the name of CustomExecMethods, then it shall be referenced on the background + * worker side later. + * + * Custom-scan provider may also have to support serialization/deserialization + * on CustomPath and CustomScanState in the future release, but not now. + */ +#define CUSTOM_NAME_MAX_LEN 64 + +/* + * Flags definitions + */ +#define CUSTOMPATH_SUPPORT_BACKWARD_SCAN 0x0001 +#define CUSTOMPATH_SUPPORT_MARK_RESTORE 0x0002 + +typedef struct CustomPathMethods +{ + const char *CustomName; + + /* Convert Path to a Plan */ + struct Plan *(*PlanCustomPath) (PlannerInfo *root, + RelOptInfo *rel, + struct CustomPath *best_path, + List *tlist, + List *clauses, + List *custom_plans); +} CustomPathMethods; + + +typedef struct CustomScanMethods +{ + const char *CustomName; + + /* Create execution state (CustomScanState) from a CustomScan plan node */ + Node *(*CreateCustomScanState) (CustomScan *cscan); +} CustomScanMethods; + + +typedef struct CustomExecMethods +{ + const char *CustomName; + + /* Executor methods: mark/restore are optional, the rest are required */ + void (*BeginCustomScan) (CustomScanState *node, + EState *estate, + int eflags); + TupleTableSlot *(*ExecCustomScan) (CustomScanState *node); + void (*EndCustomScan) (CustomScanState *node); + void (*ReScanCustomScan) (CustomScanState *node); + void (*MarkPosCustomScan) (CustomScanState *node); + void (*RestrPosCustomScan) (CustomScanState *node); + /* Optional: parallel execution support */ + Size (*EstimateDSMCustomScan) (CustomScanState *node, + ParallelContext *pcxt); + void (*InitializeDSMCustomScan) (CustomScanState *node, + ParallelContext *pcxt, + void *coordinate); + void (*InitializeWorkerCustomScan) (CustomScanState *node, + shm_toc *toc, + void *coordinate); + /* Optional: print additional information in EXPLAIN */ + void (*ExplainCustomScan) (CustomScanState *node, + List *ancestors, + ExplainState *es); +} CustomExecMethods; + +/* + * Serialization/Deserialization Support of CustomScan + */ +extern void RegisterCustomScanMethods(const CustomScanMethods *methods); +extern const CustomScanMethods *GetCustomScanMethods(const char *CustomName, + bool missing_ok); + #endif /* EXTENSIBLE_H */ diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h index 00b1d35..465d72f 100644 --- a/src/include/nodes/plannodes.h +++ b/src/include/nodes/plannodes.h @@ -555,17 +555,7 @@ typedef struct ForeignScan * a larger struct will not work. * ---------------- */ -struct CustomScan; - -typedef struct CustomScanMethods -{ - const char *CustomName; - const char *LibraryName; - const char *SymbolName; - - /* Create execution state (CustomScanState) from a CustomScan plan node */ - Node *(*CreateCustomScanState) (struct CustomScan *cscan); -} CustomScanMethods; +struct CustomScanMethods; typedef struct CustomScan { @@ -577,7 +567,7 @@ typedef struct CustomScan List *custom_scan_tlist; /* optional tlist describing scan * tuple */ Bitmapset *custom_relids; /* RTIs generated by this scan */ - const CustomScanMethods *methods; + const struct CustomScanMethods *methods; } CustomScan; /* diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h index ee7007a..32f04b2 100644 --- a/src/include/nodes/relation.h +++ b/src/include/nodes/relation.h @@ -1030,23 +1030,8 @@ typedef struct ForeignPath * FDW case, we provide a "custom_private" field in CustomPath; providers * may prefer to use that rather than define another struct type. */ -struct CustomPath; -#define CUSTOMPATH_SUPPORT_BACKWARD_SCAN 0x0001 -#define CUSTOMPATH_SUPPORT_MARK_RESTORE 0x0002 - -typedef struct CustomPathMethods -{ - const char *CustomName; - - /* Convert Path to a Plan */ - struct Plan *(*PlanCustomPath) (PlannerInfo *root, - RelOptInfo *rel, - struct CustomPath *best_path, - List *tlist, - List *clauses, - List *custom_plans); -} CustomPathMethods; +struct CustomPathMethods; typedef struct CustomPath { @@ -1054,7 +1039,7 @@ typedef struct CustomPath uint32 flags; /* mask of CUSTOMPATH_* flags, see above */ List *custom_paths; /* list of child Path nodes, if any */ List *custom_private; - const CustomPathMethods *methods; + const struct CustomPathMethods *methods; } CustomPath; /*