From: Michael Vrable <vrable@cs.hmc.edu>
Date: Thu, 2 May 2013 03:25:03 +0000 (-0700)
Subject: Factor out time formatting functions.
X-Git-Url: http://git.vrable.net/?p=cumulus.git;a=commitdiff_plain;h=5d386960f207f991833f1204748bc4323934f761

Factor out time formatting functions.
---

diff --git a/main.cc b/main.cc
index cd31189..ef8f2d7 100644
--- a/main.cc
+++ b/main.cc
@@ -814,24 +814,21 @@ int main(int argc, char *argv[])
     /* Store the time when the backup started, so it can be included in the
      * snapshot name. */
     time_t now;
-    struct tm time_buf_local, time_buf_utc;
-    char desc_buf[256];
     time(&now);
-    localtime_r(&now, &time_buf_local);
-    gmtime_r(&now, &time_buf_utc);
-    strftime(desc_buf, sizeof(desc_buf), "%Y%m%dT%H%M%S", &time_buf_utc);
+    string timestamp
+        = TimeFormat::format(now, TimeFormat::FORMAT_FILENAME, true);
 
     /* Open the local database which tracks all objects that are stored
      * remotely, for efficient incrementals.  Provide it with the name of this
      * snapshot. */
     string database_path = localdb_dir + "/localdb.sqlite";
     db = new LocalDb;
-    db->Open(database_path.c_str(), desc_buf, backup_scheme.c_str());
+    db->Open(database_path.c_str(), timestamp.c_str(), backup_scheme.c_str());
 
     tss = new TarSegmentStore(remote, db);
 
     /* Initialize the stat cache, for skipping over unchanged files. */
-    metawriter = new MetadataWriter(tss, localdb_dir.c_str(), desc_buf,
+    metawriter = new MetadataWriter(tss, localdb_dir.c_str(), timestamp.c_str(),
                                     backup_scheme.c_str());
 
     for (int i = optind; i < argc; i++) {
@@ -854,7 +851,8 @@ int main(int argc, char *argv[])
     string checksum_filename = "snapshot-";
     if (backup_scheme.size() > 0)
         checksum_filename += backup_scheme + "-";
-    checksum_filename = checksum_filename + desc_buf + "." + csum_type + "sums";
+    checksum_filename
+        = checksum_filename + timestamp + "." + csum_type + "sums";
     RemoteFile *checksum_file = remote->alloc_file(checksum_filename,
                                                    "meta");
     FILE *checksums = fdopen(checksum_file->get_fd(), "w");
@@ -905,7 +903,7 @@ int main(int argc, char *argv[])
     string desc_filename = "snapshot-";
     if (backup_scheme.size() > 0)
         desc_filename += backup_scheme + "-";
-    desc_filename = desc_filename + desc_buf + ".cumulus";
+    desc_filename = desc_filename + timestamp + ".cumulus";
 
     RemoteFile *descriptor_file = remote->alloc_file(desc_filename,
                                                      "snapshots");
@@ -925,9 +923,9 @@ int main(int argc, char *argv[])
 
     fprintf(descriptor, "Format: Cumulus Snapshot v0.11\n");
     fprintf(descriptor, "Producer: Cumulus %s\n", cumulus_version);
-    strftime(desc_buf, sizeof(desc_buf), "%Y-%m-%d %H:%M:%S %z",
-             &time_buf_local);
-    fprintf(descriptor, "Date: %s\n", desc_buf);
+    string timestamp_local
+        = TimeFormat::format(now, TimeFormat::FORMAT_LOCALTIME, false);
+    fprintf(descriptor, "Date: %s\n", timestamp_local.c_str());
     if (backup_scheme.size() > 0)
         fprintf(descriptor, "Scheme: %s\n", backup_scheme.c_str());
     fprintf(descriptor, "Root: %s\n", backup_root.c_str());
diff --git a/util.cc b/util.cc
index a7479fc..76efe0f 100644
--- a/util.cc
+++ b/util.cc
@@ -31,6 +31,8 @@
 #include <string>
 #include <sstream>
 
+#include "util.h"
+
 using std::map;
 using std::ostream;
 using std::string;
@@ -134,3 +136,24 @@ void fatal(string msg)
     fprintf(stderr, "FATAL: %s\n", msg.c_str());
     exit(1);
 }
+
+/* Available time formats. */
+const char TimeFormat::FORMAT_FILENAME[] = "%Y%m%dT%H%M%S";
+const char TimeFormat::FORMAT_ISO8601[] = "%Y-%m-%d %H:%M:%S";
+const char TimeFormat::FORMAT_LOCALTIME[] = "%Y-%m-%d %H:%M:%S %z";
+
+static size_t MAX_TIMESTAMP_LENGTH = 1024;
+
+std::string TimeFormat::format(time_t timestamp, const char *format, bool utc)
+{
+    struct tm time_buf;
+
+    if (utc)
+        gmtime_r(&timestamp, &time_buf);
+    else
+        localtime_r(&timestamp, &time_buf);
+
+    char buffer[MAX_TIMESTAMP_LENGTH];
+    strftime(buffer, MAX_TIMESTAMP_LENGTH, format, &time_buf);
+    return string(buffer);
+}
diff --git a/util.h b/util.h
index c6c6f9e..0d1b45d 100644
--- a/util.h
+++ b/util.h
@@ -36,4 +36,25 @@ void cloexec(int fd);
 
 void fatal(std::string msg) __attribute__((noreturn));
 
+/* Date/time string formatting and parsing utility functions.  All data and
+ * methods are static, so this class should not be instantiated. */
+class TimeFormat {
+public:
+    // Abbreviated time format encoded in snapshot file names.
+    static const char FORMAT_FILENAME[];
+    // A timestamp, in UTC, written out in an ISO 8601 format (compatible with
+    // the SQLite datetime function).
+    static const char FORMAT_ISO8601[];
+    // Similar to the above, but including a timezone offset.
+    static const char FORMAT_LOCALTIME[];
+
+    static std::string format(time_t timestamp, const char *format, bool utc);
+
+    static std::string isoformat(time_t timestamp)
+        { return format(timestamp, FORMAT_ISO8601, true); }
+
+private:
+    TimeFormat() { }
+};
+
 #endif // _LBS_TARSTORE_H