On Wed, Sep 30, 2020 at 04:41:51PM +0900, Michael Paquier wrote:
> This feedback has not been answered after two weeks, so I have marked
> the patch as returned with feedback.
I've rebased this patch and will register it in the next commitfest
shortly.
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
>From a1c0704a094f849a587c7332a547c89581f4f7e6 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathandboss...@gmail.com>
Date: Tue, 2 Aug 2022 16:15:01 -0700
Subject: [PATCH v2 1/1] Support COPY TO callback functions.
---
src/backend/commands/copy.c | 2 +-
src/backend/commands/copyto.c | 18 +++++++++++++++---
src/include/commands/copy.h | 3 ++-
src/tools/pgindent/typedefs.list | 1 +
4 files changed, 19 insertions(+), 5 deletions(-)
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 3ac731803b..f714c5e22e 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -304,7 +304,7 @@ DoCopy(ParseState *pstate, const CopyStmt *stmt,
cstate = BeginCopyTo(pstate, rel, query, relid,
stmt->filename, stmt->is_program,
- stmt->attlist, stmt->options);
+ NULL, stmt->attlist, stmt->options);
*processed = DoCopyTo(cstate); /* copy from database to file */
EndCopyTo(cstate);
}
diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c
index fca29a9a10..a7b8ec030d 100644
--- a/src/backend/commands/copyto.c
+++ b/src/backend/commands/copyto.c
@@ -51,6 +51,7 @@ typedef enum CopyDest
{
COPY_FILE, /* to file (or a piped program) */
COPY_FRONTEND, /* to frontend */
+ COPY_CALLBACK, /* to callback function */
} CopyDest;
/*
@@ -85,6 +86,7 @@ typedef struct CopyToStateData
List *attnumlist; /* integer list of attnums to copy */
char *filename; /* filename, or NULL for STDOUT */
bool is_program; /* is 'filename' a program to popen? */
+ copy_data_dest_cb data_dest_cb; /* function for writing data */
CopyFormatOptions opts;
Node *whereClause; /* WHERE condition (or NULL) */
@@ -247,6 +249,9 @@ CopySendEndOfRow(CopyToState cstate)
/* Dump the accumulated row as one CopyData message */
(void) pq_putmessage('d', fe_msgbuf->data, fe_msgbuf->len);
break;
+ case COPY_CALLBACK:
+ cstate->data_dest_cb(fe_msgbuf->data, fe_msgbuf->len);
+ break;
}
/* Update the progress */
@@ -344,11 +349,12 @@ BeginCopyTo(ParseState *pstate,
Oid queryRelId,
const char *filename,
bool is_program,
+ copy_data_dest_cb data_dest_cb,
List *attnamelist,
List *options)
{
CopyToState cstate;
- bool pipe = (filename == NULL);
+ bool pipe = (filename == NULL && data_dest_cb == NULL);
TupleDesc tupDesc;
int num_phys_attrs;
MemoryContext oldcontext;
@@ -656,7 +662,13 @@ BeginCopyTo(ParseState *pstate,
cstate->copy_dest = COPY_FILE; /* default */
- if (pipe)
+ if (data_dest_cb)
+ {
+ progress_vals[1] = PROGRESS_COPY_TYPE_CALLBACK;
+ cstate->copy_dest = COPY_CALLBACK;
+ cstate->data_dest_cb = data_dest_cb;
+ }
+ else if (pipe)
{
progress_vals[1] = PROGRESS_COPY_TYPE_PIPE;
@@ -769,7 +781,7 @@ EndCopyTo(CopyToState cstate)
uint64
DoCopyTo(CopyToState cstate)
{
- bool pipe = (cstate->filename == NULL);
+ bool pipe = (cstate->filename == NULL && cstate->data_dest_cb == NULL);
bool fe_copy = (pipe && whereToSendOutput == DestRemote);
TupleDesc tupDesc;
int num_phys_attrs;
diff --git a/src/include/commands/copy.h b/src/include/commands/copy.h
index cb0096aeb6..76b9d5c23f 100644
--- a/src/include/commands/copy.h
+++ b/src/include/commands/copy.h
@@ -66,6 +66,7 @@ typedef struct CopyFromStateData *CopyFromState;
typedef struct CopyToStateData *CopyToState;
typedef int (*copy_data_source_cb) (void *outbuf, int minread, int maxread);
+typedef void (*copy_data_dest_cb) (void *data, int len);
extern void DoCopy(ParseState *state, const CopyStmt *stmt,
int stmt_location, int stmt_len,
@@ -91,7 +92,7 @@ extern DestReceiver *CreateCopyDestReceiver(void);
*/
extern CopyToState BeginCopyTo(ParseState *pstate, Relation rel, RawStmt *query,
Oid queryRelId, const char *filename, bool is_program,
- List *attnamelist, List *options);
+ copy_data_dest_cb data_dest_cb, List *attnamelist, List *options);
extern void EndCopyTo(CopyToState cstate);
extern uint64 DoCopyTo(CopyToState cstate);
extern List *CopyGetAttnums(TupleDesc tupDesc, Relation rel,
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 35c9f1efce..83e5270034 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3189,6 +3189,7 @@ compare_context
config_var_value
contain_aggs_of_level_context
convert_testexpr_context
+copy_data_dest_cb
copy_data_source_cb
core_YYSTYPE
core_yy_extra_type
--
2.25.1
