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/*-------------------------------------------------------------------------
*
* copyfrom_internal.h
* Internal definitions for COPY FROM command.
*
*
* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/commands/copyfrom_internal.h
*
*-------------------------------------------------------------------------
*/
#ifndef COPYFROM_INTERNAL_H
#define COPYFROM_INTERNAL_H
#include "commands/copy.h"
#include "commands/trigger.h"
/*
* Represents the different source cases we need to worry about at
* the bottom level
*/
typedef enum CopySource
{
COPY_FILE, /* from file (or a piped program) */
COPY_OLD_FE, /* from frontend (2.0 protocol) */
COPY_NEW_FE, /* from frontend (3.0 protocol) */
COPY_CALLBACK /* from callback function */
} CopySource;
/*
* Represents the end-of-line terminator type of the input
*/
typedef enum EolType
{
EOL_UNKNOWN,
EOL_NL,
EOL_CR,
EOL_CRNL
} EolType;
/*
* Represents the heap insert method to be used during COPY FROM.
*/
typedef enum CopyInsertMethod
{
CIM_SINGLE, /* use table_tuple_insert or fdw routine */
CIM_MULTI, /* always use table_multi_insert */
CIM_MULTI_CONDITIONAL /* use table_multi_insert only if valid */
} CopyInsertMethod;
/*
* This struct contains all the state variables used throughout a COPY FROM
* operation.
*
* Multi-byte encodings: all supported client-side encodings encode multi-byte
* characters by having the first byte's high bit set. Subsequent bytes of the
* character can have the high bit not set. When scanning data in such an
* encoding to look for a match to a single-byte (ie ASCII) character, we must
* use the full pg_encoding_mblen() machinery to skip over multibyte
* characters, else we might find a false match to a trailing byte. In
* supported server encodings, there is no possibility of a false match, and
* it's faster to make useless comparisons to trailing bytes than it is to
* invoke pg_encoding_mblen() to skip over them. encoding_embeds_ascii is true
* when we have to do it the hard way.
*/
typedef struct CopyFromStateData
{
/* low-level state data */
CopySource copy_src; /* type of copy source */
FILE *copy_file; /* used if copy_src == COPY_FILE */
StringInfo fe_msgbuf; /* used if copy_src == COPY_NEW_FE */
bool reached_eof; /* true if we read to end of copy data (not
* all copy_src types maintain this) */
EolType eol_type; /* EOL type of input */
int file_encoding; /* file or remote side's character encoding */
bool need_transcoding; /* file encoding diff from server? */
bool encoding_embeds_ascii; /* ASCII can be non-first byte? */
/* parameters from the COPY command */
Relation rel; /* relation to copy from */
List *attnumlist; /* integer list of attnums to copy */
char *filename; /* filename, or NULL for STDIN */
bool is_program; /* is 'filename' a program to popen? */
copy_data_source_cb data_source_cb; /* function for reading data */
CopyFormatOptions opts;
bool *convert_select_flags; /* per-column CSV/TEXT CS flags */
Node *whereClause; /* WHERE condition (or NULL) */
/* these are just for error messages, see CopyFromErrorCallback */
const char *cur_relname; /* table name for error messages */
uint64 cur_lineno; /* line number for error messages */
const char *cur_attname; /* current att for error messages */
const char *cur_attval; /* current att value for error messages */
/*
* Working state
*/
MemoryContext copycontext; /* per-copy execution context */
AttrNumber num_defaults;
FmgrInfo *in_functions; /* array of input functions for each attrs */
Oid *typioparams; /* array of element types for in_functions */
int *defmap; /* array of default att numbers */
ExprState **defexprs; /* array of default att expressions */
bool volatile_defexprs; /* is any of defexprs volatile? */
List *range_table;
ExprState *qualexpr;
TransitionCaptureState *transition_capture;
/*
* These variables are used to reduce overhead in COPY FROM.
*
* attribute_buf holds the separated, de-escaped text for each field of
* the current line. The CopyReadAttributes functions return arrays of
* pointers into this buffer. We avoid palloc/pfree overhead by re-using
* the buffer on each cycle.
*
* In binary COPY FROM, attribute_buf holds the binary data for the
* current field, but the usage is otherwise similar.
*/
StringInfoData attribute_buf;
/* field raw data pointers found by COPY FROM */
int max_fields;
char **raw_fields;
/*
* Similarly, line_buf holds the whole input line being processed. The
* input cycle is first to read the whole line into line_buf, convert it
* to server encoding there, and then extract the individual attribute
* fields into attribute_buf. line_buf is preserved unmodified so that we
* can display it in error messages if appropriate. (In binary mode,
* line_buf is not used.)
*/
StringInfoData line_buf;
bool line_buf_converted; /* converted to server encoding? */
bool line_buf_valid; /* contains the row being processed? */
/*
* Finally, raw_buf holds raw data read from the data source (file or
* client connection). In text mode, CopyReadLine parses this data
* sufficiently to locate line boundaries, then transfers the data to
* line_buf and converts it. In binary mode, CopyReadBinaryData fetches
* appropriate amounts of data from this buffer. In both modes, we
* guarantee that there is a \0 at raw_buf[raw_buf_len].
*/
#define RAW_BUF_SIZE 65536 /* we palloc RAW_BUF_SIZE+1 bytes */
char *raw_buf;
int raw_buf_index; /* next byte to process */
int raw_buf_len; /* total # of bytes stored */
/* Shorthand for number of unconsumed bytes available in raw_buf */
#define RAW_BUF_BYTES(cstate) ((cstate)->raw_buf_len - (cstate)->raw_buf_index)
} CopyFromStateData;
extern void ReceiveCopyBegin(CopyFromState cstate);
extern void ReceiveCopyBinaryHeader(CopyFromState cstate);
#endif /* COPYFROM_INTERNAL_H */
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