Use an enum instead of two bools to indicate wal inclusion in base backups

This makes the code easier to read as it becomes more explicit what the
different allowed combinations really are.

Suggested by Michael Paquier

diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 3f83d87e506b0a883dce5a7a16e373274c0b9171..8ebf24e7717ed3ddee7a5bf0912500b1491d7cbb 100644 (file)
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -61,6 +61,16 @@ typedef struct TablespaceList
  */
 #define MINIMUM_VERSION_FOR_PG_WAL 100000
 
+/*
+ * Different ways to include WAL
+ */
+typedef enum
+{
+   NO_WAL,
+   FETCH_WAL,
+   STREAM_WAL
+} IncludeWal;
+
 /* Global options */
 static char *basedir = NULL;
 static TablespaceList tablespace_dirs = {NULL, NULL};
@@ -71,8 +81,7 @@ static bool noclean = false;
 static bool showprogress = false;
 static int verbose = 0;
 static int compresslevel = 0;
-static bool includewal = true;
-static bool streamwal = true;
+static IncludeWal includewal = STREAM_WAL;
 static bool fastcheckpoint = false;
 static bool writerecoveryconf = false;
 static bool do_sync = true;
@@ -1697,7 +1706,7 @@ BaseBackup(void)
     * If WAL streaming was requested, also check that the server is new
     * enough for that.
     */
-   if (streamwal && !CheckServerVersionForStreaming(conn))
+   if (includewal == STREAM_WAL && !CheckServerVersionForStreaming(conn))
    {
        /*
         * Error message already written in CheckServerVersionForStreaming(),
@@ -1731,9 +1740,9 @@ BaseBackup(void)
        psprintf("BASE_BACKUP LABEL '%s' %s %s %s %s %s %s",
                 escaped_label,
                 showprogress ? "PROGRESS" : "",
-                includewal && !streamwal ? "WAL" : "",
+                includewal == FETCH_WAL ? "WAL" : "",
                 fastcheckpoint ? "FAST" : "",
-                includewal ? "NOWAIT" : "",
+                includewal == NO_WAL ? "" : "NOWAIT",
                 maxrate_clause ? maxrate_clause : "",
                 format == 't' ? "TABLESPACE_MAP" : "");
 
@@ -1776,7 +1785,7 @@ BaseBackup(void)
    PQclear(res);
    MemSet(xlogend, 0, sizeof(xlogend));
 
-   if (verbose && includewal)
+   if (verbose && includewal != NO_WAL)
        fprintf(stderr, _("transaction log start point: %s on timeline %u\n"),
                xlogstart, starttli);
 
@@ -1833,7 +1842,7 @@ BaseBackup(void)
     * If we're streaming WAL, start the streaming session before we start
     * receiving the actual data chunks.
     */
-   if (streamwal)
+   if (includewal == STREAM_WAL)
    {
        if (verbose)
            fprintf(stderr, _("%s: starting background WAL receiver\n"),
@@ -1879,7 +1888,7 @@ BaseBackup(void)
        disconnect_and_exit(1);
    }
    strlcpy(xlogend, PQgetvalue(res, 0, 0), sizeof(xlogend));
-   if (verbose && includewal)
+   if (verbose && includewal != NO_WAL)
        fprintf(stderr, "transaction log end point: %s\n", xlogend);
    PQclear(res);
 
@@ -2117,20 +2126,17 @@ main(int argc, char **argv)
                if (strcmp(optarg, "n") == 0 ||
                    strcmp(optarg, "none") == 0)
                {
-                   includewal = false;
-                   streamwal = false;
+                   includewal = NO_WAL;
                }
                else if (strcmp(optarg, "f") == 0 ||
                    strcmp(optarg, "fetch") == 0)
                {
-                   includewal = true;
-                   streamwal = false;
+                   includewal = FETCH_WAL;
                }
                else if (strcmp(optarg, "s") == 0 ||
                         strcmp(optarg, "stream") == 0)
                {
-                   includewal = true;
-                   streamwal = true;
+                   includewal = STREAM_WAL;
                }
                else
                {
@@ -2261,7 +2267,7 @@ main(int argc, char **argv)
        exit(1);
    }
 
-   if (format == 't' && streamwal && strcmp(basedir, "-") == 0)
+   if (format == 't' && includewal == STREAM_WAL && strcmp(basedir, "-") == 0)
    {
        fprintf(stderr,
            _("%s: cannot stream transaction logs in tar mode to stdout\n"),
@@ -2271,7 +2277,7 @@ main(int argc, char **argv)
        exit(1);
    }
 
-   if (replication_slot && !streamwal)
+   if (replication_slot && includewal != STREAM_WAL)
    {
        fprintf(stderr,
            _("%s: replication slots can only be used with WAL streaming\n"),