From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Wed, 12 Dec 2007 01:49:44 +0000 (-0800)
Subject: Add "intent" field to a snapshot.
X-Git-Url: https://git.vrable.net/?a=commitdiff_plain;h=cc2d3611ed50f5965a9138ffaf3262417993c4f8;p=cumulus.git

Add "intent" field to a snapshot.

This field is intended to indicate how long the backup might be kept or
what backup schedule the given snapshot is part of--for example 1 for a
daily backup, 7 for a weekly backup.

This might be used when performing segment cleaning or deleting old
snapshots, but for now the information is just stored in the local
database.
---

diff --git a/contrib/upgrade0.6-localdb.sql b/contrib/upgrade0.6-localdb.sql
index dbf7789..d1449ac 100644
--- a/contrib/upgrade0.6-localdb.sql
+++ b/contrib/upgrade0.6-localdb.sql
@@ -7,7 +7,8 @@
 -- Database schema changes: the size and mtime columns were added to the
 -- segments table, and the segments_used table was added.  Rather than upgrade
 -- the segments table in-place, we create a new table and then rename it over
--- the old segments table.
+-- the old segments table.  The intent column was also added to the snapshots
+-- table.
 create table segments_new (
     segmentid integer primary key,
     segment text unique not null,
@@ -23,6 +24,12 @@ create table segments_used (
     utilization real
 );
 
+alter table snapshots add column intent real;
+
+-- Initialize the intent column; set all old snapshots to have intent 1
+-- (intended to be a daily snapshot).
+update snapshots set intent = 1;
+
 -- Compute the size of each of the segments, if possible, based on our
 -- knowledge of the objects stored in them.
 insert into segments_new
diff --git a/localdb.cc b/localdb.cc
index 1509b61..004391b 100644
--- a/localdb.cc
+++ b/localdb.cc
@@ -46,7 +46,7 @@ void LocalDb::ReportError(int rc)
 }
 
 void LocalDb::Open(const char *path, const char *snapshot_name,
-                   const char *snapshot_scheme)
+                   const char *snapshot_scheme, double intent)
 {
     int rc;
 
@@ -69,8 +69,8 @@ void LocalDb::Open(const char *path, const char *snapshot_name,
     /* Insert this snapshot into the database, and determine the integer key
      * which will be used to identify it. */
     sqlite3_stmt *stmt = Prepare("insert into "
-                                 "snapshots(name, scheme, timestamp) "
-                                 "values (?, ?, julianday('now'))");
+                                 "snapshots(name, scheme, timestamp, intent) "
+                                 "values (?, ?, julianday('now'), ?)");
     sqlite3_bind_text(stmt, 1, snapshot_name, strlen(snapshot_name),
                       SQLITE_TRANSIENT);
     if (snapshot_scheme == NULL)
@@ -78,6 +78,7 @@ void LocalDb::Open(const char *path, const char *snapshot_name,
     else
         sqlite3_bind_text(stmt, 2, snapshot_scheme, strlen(snapshot_scheme),
                           SQLITE_TRANSIENT);
+    sqlite3_bind_double(stmt, 3, intent);
 
     rc = sqlite3_step(stmt);
     if (rc != SQLITE_DONE) {
diff --git a/localdb.h b/localdb.h
index bef9286..69fb330 100644
--- a/localdb.h
+++ b/localdb.h
@@ -22,7 +22,7 @@
 class LocalDb {
 public:
     void Open(const char *path, const char *snapshot_name,
-              const char *snapshot_scheme);
+              const char *snapshot_scheme, double intent);
     void Close();
     void StoreObject(const ObjectReference& ref,
                      const std::string &checksum, int64_t size, double age);
diff --git a/scandir.cc b/scandir.cc
index cf66ea6..f653f43 100644
--- a/scandir.cc
+++ b/scandir.cc
@@ -57,6 +57,11 @@ LocalDb *db;
 /* Keep track of all segments which are needed to reconstruct the snapshot. */
 std::set<string> segment_list;
 
+/* Snapshot intent: 1=daily, 7=weekly, etc.  This is not used directly, but is
+ * stored in the local database and can help guide segment cleaning and
+ * snapshot expiration policies. */
+double snapshot_intent = 1.0;
+
 /* Selection of files to include/exclude in the snapshot. */
 std::list<string> includes;         // Paths in which files should be saved
 std::list<string> excludes;         // Paths which will not be saved
@@ -557,7 +562,9 @@ void usage(const char *program)
         "                           (defaults to \".bz2\")\n"
         "  --signature-filter=COMMAND\n"
         "                       program though which to filter descriptor\n"
-        "  --scheme=NAME        optional name for this snapshot\n",
+        "  --scheme=NAME        optional name for this snapshot\n"
+        "  --intent=FLOAT       intended backup type: 1=daily, 7=weekly, ...\n"
+        "                           (defaults to \"1\")\n",
         lbs_version, program
     );
 }
@@ -578,6 +585,7 @@ int main(int argc, char *argv[])
             {"dest", 1, 0, 0},              // 4
             {"scheme", 1, 0, 0},            // 5
             {"signature-filter", 1, 0, 0},  // 6
+            {"intent", 1, 0, 0},            // 7
             {NULL, 0, 0, 0},
         };
 
@@ -613,6 +621,11 @@ int main(int argc, char *argv[])
             case 6:     // --signature-filter
                 signature_filter = optarg;
                 break;
+            case 7:     // --intent
+                snapshot_intent = atof(optarg);
+                if (snapshot_intent <= 0)
+                    snapshot_intent = 1;
+                break;
             default:
                 fprintf(stderr, "Unhandled long option!\n");
                 return 1;
@@ -683,7 +696,8 @@ int main(int argc, char *argv[])
     string database_path = localdb_dir + "/localdb.sqlite";
     db = new LocalDb;
     db->Open(database_path.c_str(), desc_buf,
-             backup_scheme.size() ? backup_scheme.c_str() : NULL);
+             backup_scheme.size() ? backup_scheme.c_str() : NULL,
+             snapshot_intent);
 
     tss = new TarSegmentStore(backup_dest, db);
 
diff --git a/schema.sql b/schema.sql
index e0f16a6..3cf175b 100644
--- a/schema.sql
+++ b/schema.sql
@@ -8,7 +8,8 @@ create table snapshots (
     snapshotid integer primary key,
     name text not null,
     scheme text,
-    timestamp real
+    timestamp real,
+    intent real
 );
 
 -- List of segments which have been created.