Files
openGauss-server/src/bin/psql/copy.cpp
2020-06-30 17:38:27 +08:00

592 lines
18 KiB
C++

/*
* psql - the PostgreSQL interactive terminal
*
* Copyright (c) 2000-2012, PostgreSQL Global Development Group
*
* src/bin/psql/copy.c
*/
#include "settings.h"
#include "postgres_fe.h"
#include "copy.h"
#include <signal.h>
#include <sys/stat.h>
#ifndef WIN32
#include <unistd.h> /* for isatty */
#else
#include <io.h> /* I think */
#endif
#include "libpq/libpq-fe.h"
#include "libpq/pqexpbuffer.h"
#include "pqsignal.h"
#include "dumputils.h"
#include "common.h"
#include "prompt.h"
#include "stringutils.h"
#include <cxxabi.h>
/*
* parse_slash_copy
* -- parses \copy command line
*
* The documented syntax is:
* \copy tablename [(columnlist)] from|to filename [options]
* \copy ( select stmt ) to filename [options]
*
* An undocumented fact is that you can still write BINARY before the
* tablename; this is a hangover from the pre-7.3 syntax. The options
* syntax varies across backend versions, but we avoid all that mess
* by just transmitting the stuff after the filename literally.
*
* table name can be double-quoted and can have a schema part.
* column names can be double-quoted.
* filename can be single-quoted like SQL literals.
*
* returns a malloc'ed structure with the options, or NULL on parsing error
*/
struct copy_options {
char* before_tofrom; /* COPY string before TO/FROM */
char* after_tofrom; /* COPY string after TO/FROM filename */
char* file; /* NULL = stdin/stdout */
bool psql_inout; /* true = use psql stdin/stdout */
bool from; /* true = FROM, false = TO */
};
static void free_copy_options(struct copy_options* ptr)
{
if (ptr == NULL)
return;
free(ptr->before_tofrom);
ptr->before_tofrom = NULL;
free(ptr->after_tofrom);
ptr->after_tofrom = NULL;
free(ptr->file);
ptr->file = NULL;
free(ptr);
}
/* concatenate "more" onto "var", freeing the original value of *var */
static void xstrcat(char** var, const char* more)
{
/* strlen will crash when NULL passed in */
if (var == NULL || *var == NULL || more == NULL) {
psql_error("trying to xstrcat a NULL \n");
exit(EXIT_FAILURE);
return;
}
errno_t err = EOK;
char* newvar = NULL;
size_t varlen = strlen(*var);
size_t morelen = strlen(more);
size_t newvarsz = varlen + morelen + 1;
newvar = (char*)pg_malloc(newvarsz);
err = strcpy_s(newvar, newvarsz, *var);
check_strcpy_s(err);
err = strcat_s(newvar, newvarsz, more);
check_strcat_s(err);
free(*var);
*var = newvar;
}
static struct copy_options* parse_slash_copy(const char* args)
{
struct copy_options* result = NULL;
char* token = NULL;
const char* whitespace = " \t\n\r";
char nonstd_backslash = standard_strings() ? 0 : '\\';
if (args == NULL) {
psql_error("\\copy: arguments required\n");
return NULL;
}
result = (struct copy_options*)pg_calloc(1, sizeof(struct copy_options));
result->before_tofrom = pg_strdup(""); /* initialize for appending */
token = strtokx(args, whitespace, ".,()", "\"", 0, false, false, pset.encoding);
if (token == NULL)
goto error;
/* The following can be removed when we drop 7.3 syntax support */
if (pg_strcasecmp(token, "binary") == 0) {
xstrcat(&result->before_tofrom, token);
token = strtokx(NULL, whitespace, ".,()", "\"", 0, false, false, pset.encoding);
if (token == NULL)
goto error;
}
/* Handle COPY (SELECT) case */
if (token[0] == '(') {
int parens = 1;
while (parens > 0) {
xstrcat(&result->before_tofrom, " ");
xstrcat(&result->before_tofrom, token);
token = strtokx(NULL, whitespace, "()", "\"'", nonstd_backslash, true, false, pset.encoding);
if (token == NULL)
goto error;
if (token[0] == '(') {
parens++;
} else if (token[0] == ')') {
parens--;
}
}
}
xstrcat(&result->before_tofrom, " ");
xstrcat(&result->before_tofrom, token);
token = strtokx(NULL, whitespace, ".,()", "\"", 0, false, false, pset.encoding);
if (token == NULL)
goto error;
/*
* strtokx() will not have returned a multi-character token starting with
* '.', so we don't need strcmp() here. Likewise for '(', etc, below.
*/
if (token[0] == '.') {
/* handle schema . table */
xstrcat(&result->before_tofrom, token);
token = strtokx(NULL, whitespace, ".,()", "\"", 0, false, false, pset.encoding);
if (token == NULL)
goto error;
xstrcat(&result->before_tofrom, token);
token = strtokx(NULL, whitespace, ".,()", "\"", 0, false, false, pset.encoding);
if (token == NULL)
goto error;
}
if (token[0] == '(') {
/* handle parenthesized column list */
for (;;) {
xstrcat(&result->before_tofrom, " ");
xstrcat(&result->before_tofrom, token);
token = strtokx(NULL, whitespace, "()", "\"", 0, false, false, pset.encoding);
if (token == NULL) {
goto error;
}
if (token[0] == ')') {
break;
}
}
xstrcat(&result->before_tofrom, " ");
xstrcat(&result->before_tofrom, token);
token = strtokx(NULL, whitespace, ".,()", "\"", 0, false, false, pset.encoding);
if (token == NULL)
goto error;
}
if (pg_strcasecmp(token, "from") == 0)
result->from = true;
else if (pg_strcasecmp(token, "to") == 0)
result->from = false;
else
goto error;
token = strtokx(NULL, whitespace, ";", "'", 0, false, true, pset.encoding);
if (token == NULL)
goto error;
if (pg_strcasecmp(token, "stdin") == 0 || pg_strcasecmp(token, "stdout") == 0) {
result->psql_inout = false;
result->file = NULL;
} else if (pg_strcasecmp(token, "pstdin") == 0 || pg_strcasecmp(token, "pstdout") == 0) {
result->psql_inout = true;
result->file = NULL;
} else {
result->psql_inout = false;
result->file = pg_strdup(token);
expand_tilde(&result->file);
}
/* Collect the rest of the line (COPY options) */
token = strtokx(NULL, "", NULL, NULL, 0, false, false, pset.encoding);
if (NULL != token)
result->after_tofrom = pg_strdup(token);
return result;
error:
if (NULL != token)
psql_error("\\copy: parse error at \"%s\"\n", token);
else
psql_error("\\copy: parse error at end of line\n");
free_copy_options(result);
return NULL;
}
/*
* Execute a \copy command (frontend copy). We have to open a file, then
* submit a COPY query to the backend and either feed it data from the
* file or route its response into the file.
*/
bool do_copy(const char* args)
{
PQExpBufferData query;
FILE* copystream = NULL;
FILE* save_file = NULL;
FILE** override_file = NULL;
struct copy_options* options = NULL;
bool success = false;
struct stat st;
/* parse options */
options = parse_slash_copy(args);
if (options == NULL)
return false;
/* prepare to read or write the target file */
if (NULL != options->file)
canonicalize_path(options->file);
if (options->from) {
override_file = &pset.cur_cmd_source;
if (NULL != options->file)
copystream = fopen(options->file, PG_BINARY_R);
else if (!options->psql_inout)
copystream = pset.cur_cmd_source;
else
copystream = stdin;
} else {
override_file = &pset.queryFout;
if (options->file != NULL) {
canonicalize_path(options->file);
copystream = fopen(options->file, PG_BINARY_W);
} else if (!options->psql_inout)
copystream = pset.queryFout;
else
copystream = stdout;
}
if (copystream == NULL) {
psql_error("%s: %s\n", options->file, strerror(errno));
free_copy_options(options);
return false;
}
/* make sure the specified file is not a directory */
fstat(fileno(copystream), &st);
if (S_ISDIR(st.st_mode)) {
fclose(copystream);
psql_error("%s: cannot copy from/to a directory\n", options->file);
free_copy_options(options);
return false;
}
/* build the command we will send to the backend */
initPQExpBuffer(&query);
printfPQExpBuffer(&query, "COPY ");
appendPQExpBufferStr(&query, options->before_tofrom);
if (options->from)
appendPQExpBuffer(&query, " FROM STDIN ");
else
appendPQExpBuffer(&query, " TO STDOUT ");
if (NULL != options->after_tofrom)
appendPQExpBufferStr(&query, options->after_tofrom);
/* Run it like a user command, interposing the data source or sink. */
save_file = *override_file;
*override_file = copystream;
success = SendQuery(query.data);
*override_file = save_file;
termPQExpBuffer(&query);
if (options->file != NULL) {
if (fclose(copystream) != 0) {
psql_error("%s: %s\n", options->file, strerror(errno));
success = false;
}
}
free_copy_options(options);
return success;
}
/*
* Functions for handling COPY IN/OUT data transfer.
*
* If you want to use COPY TO STDOUT/FROM STDIN in your application,
* this is the code to steal ;)
*/
/*
* handleCopyOut
* receives data as a result of a COPY ... TO STDOUT command
*
* conn should be a database connection that you just issued COPY TO on
* and got back a PGRES_COPY_OUT result.
* copystream is the file stream for the data to go to.
*
* result is true if successful, false if not.
*/
bool handleCopyOut(PGconn* conn, FILE* copystream)
{
bool OK = true;
char* buf = NULL;
int ret;
PGresult* res = NULL;
for (;;) {
ret = PQgetCopyData(conn, &buf, 0);
if (ret < 0) {
break; /* done or error */
}
if (NULL != buf) {
if (fwrite(buf, 1, ret, copystream) != (unsigned int)(ret)) {
if (OK) /* complain only once, keep reading data */
psql_error("could not write COPY data: %s\n", strerror(errno));
OK = false;
}
PQfreemem(buf);
}
}
if (OK && fflush(copystream)) {
psql_error("could not write COPY data: %s\n", strerror(errno));
OK = false;
}
if (ret == -2) {
psql_error("COPY data transfer failed: %s", PQerrorMessage(conn));
OK = false;
}
/*
* Check command status and return to normal libpq state. After a
* client-side error, the server will remain ready to deliver data. The
* cleanest thing is to fully drain and discard that data. If the
* client-side error happened early in a large file, this takes a long
* time. Instead, take advantage of the fact that PQexec() will silently
* end any ongoing PGRES_COPY_OUT state. This does cause us to lose the
* results of any commands following the COPY in a single command string.
* It also only works for protocol version 3. XXX should we clean up
* using the slow way when the connection is using protocol version 2?
*
* We must not ever return with the status still PGRES_COPY_OUT. Our
* caller is unable to distinguish that situation from reaching the next
* COPY in a command string that happened to contain two consecutive COPY
* TO STDOUT commands. We trust that no condition can make PQexec() fail
* indefinitely while retaining status PGRES_COPY_OUT.
*/
while (res = PQgetResult(conn), PQresultStatus(res) == PGRES_COPY_OUT) {
OK = false;
PQclear(res);
PQexec(conn, "-- clear PGRES_COPY_OUT state");
}
if (PQresultStatus(res) != PGRES_COMMAND_OK) {
psql_error("%s", PQerrorMessage(conn));
OK = false;
}
PQclear(res);
return OK;
}
/*
* handleCopyIn
* sends data to complete a COPY ... FROM STDIN command
*
* conn should be a database connection that you just issued COPY FROM on
* and got back a PGRES_COPY_IN result.
* copystream is the file stream to read the data from.
* isbinary can be set from PQbinaryTuples().
*
* result is true if successful, false if not.
*/
/* read chunk size for COPY IN - size is not critical */
#define COPYBUFSIZ 8192
bool handleCopyIn(PGconn* conn, FILE* copystream, bool isbinary)
{
bool OK = false;
const char* prompt = NULL;
char buf[COPYBUFSIZ];
PGresult* res = NULL;
/*
* Establish longjmp destination for exiting from wait-for-input. (This is
* only effective while sigint_interrupt_enabled is TRUE.)
*/
if (sigsetjmp(sigint_interrupt_jmp, 1) != 0) {
/* got here with longjmp */
/* Terminate data transfer */
(void)PQputCopyEnd(conn, _("canceled by user"));
OK = false;
goto copyin_cleanup;
}
/* Prompt if interactive input */
if (isatty(fileno(copystream))) {
if (!pset.quiet)
puts(_("Enter data to be copied followed by a newline.\n"
"End with a backslash and a period on a line by itself."));
prompt = get_prompt(PROMPT_COPY);
} else
prompt = NULL;
OK = true;
if (isbinary) {
/* interactive input probably silly, but give one prompt anyway */
if (NULL != prompt) {
fputs(prompt, stdout);
fflush(stdout);
}
for (;;) {
int buflen;
/* enable longjmp while waiting for input */
sigint_interrupt_enabled = true;
buflen = fread(buf, 1, COPYBUFSIZ, copystream);
sigint_interrupt_enabled = false;
if (buflen <= 0) {
break;
}
if (PQputCopyData(conn, buf, buflen) <= 0) {
OK = false;
break;
}
}
} else {
bool copydone = false;
while (!copydone) { /* for each input line ... */
bool firstload = false;
bool linedone = false;
if (NULL != prompt) {
fputs(prompt, stdout);
fflush(stdout);
}
firstload = true;
linedone = false;
while (!linedone) { /* for each bufferload in line ... */
size_t linelen;
char* fgresult = NULL;
/* enable longjmp while waiting for input */
sigint_interrupt_enabled = true;
/* Database Security: Data importing/dumping support AES128. */
if (!pset.decryptInfo.encryptInclude) {
fgresult = fgets(pset.decryptInfo.currLine, sizeof(pset.decryptInfo.currLine), copystream);
} else {
fgresult = getLineFromAesEncryptFile(copystream, &pset.decryptInfo);
}
sigint_interrupt_enabled = false;
if (fgresult == NULL) {
copydone = true;
break;
}
if (!pset.decryptInfo.encryptInclude) {
linelen = strlen(pset.decryptInfo.currLine);
/* current line is done? */
if (linelen > 0 && pset.decryptInfo.currLine[linelen - 1] == '\n')
linedone = true;
/* check for EOF marker, but not on a partial line */
if (firstload) {
if (strcmp(pset.decryptInfo.currLine, "\\.\n") == 0 ||
strcmp(pset.decryptInfo.currLine, "\\.\r\n") == 0) {
copydone = true;
break;
}
firstload = false;
}
if (PQputCopyData(conn, pset.decryptInfo.currLine, linelen) <= 0) {
OK = false;
copydone = true;
break;
}
} else {
linelen = strlen((const char*)pset.decryptInfo.decryptBuff);
/* current line is done? */
if (linelen > 0 && pset.decryptInfo.decryptBuff[linelen - 1] == '\n')
linedone = true;
/* check for EOF marker, but not on a partial line */
if (firstload) {
if (strncmp((const char*)pset.decryptInfo.decryptBuff, "\\.\n", strlen("\\.\n")) == 0 ||
strncmp((const char*)pset.decryptInfo.decryptBuff, "\\.\r\n", strlen("\\.\n")) == 0) {
copydone = true;
break;
}
firstload = false;
}
if (PQputCopyData(conn, (const char*)pset.decryptInfo.decryptBuff, linelen) <= 0) {
OK = false;
copydone = true;
break;
}
}
}
if (copystream == pset.cur_cmd_source)
pset.lineno++;
}
}
/* Check for read error */
if (ferror(copystream))
OK = false;
/* Terminate data transfer */
if (PQputCopyEnd(conn, OK ? NULL : _("aborted because of read failure")) <= 0)
OK = false;
copyin_cleanup:
/*
* Check command status and return to normal libpq state
*
* We must not ever return with the status still PGRES_COPY_IN. Our
* caller is unable to distinguish that situation from reaching the next
* COPY in a command string that happened to contain two consecutive COPY
* FROM STDIN commands. XXX if something makes PQputCopyEnd() fail
* indefinitely while retaining status PGRES_COPY_IN, we get an infinite
* loop. This is more realistic than handleCopyOut()'s counterpart risk.
*/
while (res = PQgetResult(conn), PQresultStatus(res) == PGRES_COPY_IN) {
OK = false;
PQclear(res);
PQputCopyEnd(pset.db, _("trying to exit copy mode"));
}
if (PQresultStatus(res) != PGRES_COMMAND_OK) {
psql_error("%s", PQerrorMessage(conn));
OK = false;
}
PQclear(res);
return OK;
}