backup_label.h File Reference

#include "access/xlogdefs.h"
#include "common/checksum_helper.h"
#include "lib/stringinfo.h"

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Functions
void	parse_backup_label (char *filename, StringInfo buf, TimeLineID *start_tli, XLogRecPtr *start_lsn, TimeLineID *previous_tli, XLogRecPtr *previous_lsn)
void	write_backup_label (char *output_directory, StringInfo buf, pg_checksum_type checksum_type, struct manifest_writer *mwriter)

Function Documentation

parse_backup_label()

void parse_backup_label	(	char *	filename,
		StringInfo	buf,
		TimeLineID *	start_tli,
		XLogRecPtr *	start_lsn,
		TimeLineID *	previous_tli,
		XLogRecPtr *	previous_lsn
	)

Definition at line 45 of file backup_label.c.

{
    int         found = 0;
 
    *start_tli = 0;
    *start_lsn = InvalidXLogRecPtr;
    *previous_tli = 0;
    *previous_lsn = InvalidXLogRecPtr;
 
    while (buf->cursor < buf->len)
    {
        char       *s = &buf->data[buf->cursor];
        int         eo = get_eol_offset(buf);
        char       *e = &buf->data[eo];
        char       *c;
 
        if (line_starts_with(s, e, "START WAL LOCATION: ", &s))
        {
            if (!parse_lsn(s, e, start_lsn, &c))
                pg_fatal("%s: could not parse %s",
                         filename, "START WAL LOCATION");
            if (c >= e || *c != ' ')
                pg_fatal("%s: improper terminator for %s",
                         filename, "START WAL LOCATION");
            found |= 1;
        }
        else if (line_starts_with(s, e, "START TIMELINE: ", &s))
        {
            if (!parse_tli(s, e, start_tli))
                pg_fatal("%s: could not parse TLI for %s",
                         filename, "START TIMELINE");
            if (*start_tli == 0)
                pg_fatal("%s: invalid TLI", filename);
            found |= 2;
        }
        else if (line_starts_with(s, e, "INCREMENTAL FROM LSN: ", &s))
        {
            if (!parse_lsn(s, e, previous_lsn, &c))
                pg_fatal("%s: could not parse %s",
                         filename, "INCREMENTAL FROM LSN");
            if (c >= e || *c != '\n')
                pg_fatal("%s: improper terminator for %s",
                         filename, "INCREMENTAL FROM LSN");
            found |= 4;
        }
        else if (line_starts_with(s, e, "INCREMENTAL FROM TLI: ", &s))
        {
            if (!parse_tli(s, e, previous_tli))
                pg_fatal("%s: could not parse %s",
                         filename, "INCREMENTAL FROM TLI");
            if (*previous_tli == 0)
                pg_fatal("%s: invalid TLI", filename);
            found |= 8;
        }
 
        buf->cursor = eo;
    }
 
    if ((found & 1) == 0)
        pg_fatal("%s: could not find %s", filename, "START WAL LOCATION");
    if ((found & 2) == 0)
        pg_fatal("%s: could not find %s", filename, "START TIMELINE");
    if ((found & 4) != 0 && (found & 8) == 0)
        pg_fatal("%s: %s requires %s", filename,
                 "INCREMENTAL FROM LSN", "INCREMENTAL FROM TLI");
    if ((found & 8) != 0 && (found & 4) == 0)
        pg_fatal("%s: %s requires %s", filename,
                 "INCREMENTAL FROM TLI", "INCREMENTAL FROM LSN");
}

References buf, filename, get_eol_offset(), InvalidXLogRecPtr, line_starts_with(), parse_lsn(), parse_tli(), and pg_fatal.

Referenced by check_backup_label_files().

write_backup_label()

void write_backup_label	(	char *	output_directory,
		StringInfo	buf,
		pg_checksum_type	checksum_type,
		struct manifest_writer *	mwriter
	)

Definition at line 127 of file backup_label.c.

{
    char        output_filename[MAXPGPATH];
    int         output_fd;
    pg_checksum_context checksum_ctx;
    uint8       checksum_payload[PG_CHECKSUM_MAX_LENGTH];
    int         checksum_length;
 
    pg_checksum_init(&checksum_ctx, checksum_type);
 
    snprintf(output_filename, MAXPGPATH, "%s/backup_label", output_directory);
 
    if ((output_fd = open(output_filename,
                          O_WRONLY | O_CREAT | O_EXCL | PG_BINARY,
                          pg_file_create_mode)) < 0)
        pg_fatal("could not open file \"%s\": %m", output_filename);
 
    while (buf->cursor < buf->len)
    {
        char       *s = &buf->data[buf->cursor];
        int         eo = get_eol_offset(buf);
        char       *e = &buf->data[eo];
 
        if (!line_starts_with(s, e, "INCREMENTAL FROM LSN: ", NULL) &&
            !line_starts_with(s, e, "INCREMENTAL FROM TLI: ", NULL))
        {
            ssize_t     wb;
 
            wb = write(output_fd, s, e - s);
            if (wb != e - s)
            {
                if (wb < 0)
                    pg_fatal("could not write file \"%s\": %m", output_filename);
                else
                    pg_fatal("could not write file \"%s\": wrote only %d of %d bytes",
                             output_filename, (int) wb, (int) (e - s));
            }
            if (pg_checksum_update(&checksum_ctx, (uint8 *) s, e - s) < 0)
                pg_fatal("could not update checksum of file \"%s\"",
                         output_filename);
        }
 
        buf->cursor = eo;
    }
 
    if (close(output_fd) != 0)
        pg_fatal("could not close \"%s\": %m", output_filename);
 
    checksum_length = pg_checksum_final(&checksum_ctx, checksum_payload);
 
    if (mwriter != NULL)
    {
        struct stat sb;
 
        /*
         * We could track the length ourselves, but must stat() to get the
         * mtime.
         */
        if (stat(output_filename, &sb) < 0)
            pg_fatal("could not stat file \"%s\": %m", output_filename);
        add_file_to_manifest(mwriter, "backup_label", sb.st_size,
                             sb.st_mtime, checksum_type,
                             checksum_length, checksum_payload);
    }
}

References add_file_to_manifest(), buf, close, get_eol_offset(), line_starts_with(), MAXPGPATH, output_filename, PG_BINARY, pg_checksum_final(), pg_checksum_init(), PG_CHECKSUM_MAX_LENGTH, pg_checksum_update(), pg_fatal, pg_file_create_mode, snprintf, stat::st_mtime, stat::st_size, stat, and write.

Referenced by main().