Include sizes in references to blocks in each file's data list.

[cumulus.git] / localdb.cc

diff --git a/localdb.cc b/localdb.cc
index 251148b..17337f0 100644 (file)
--- a/localdb.cc
+++ b/localdb.cc
@@ -32,6 +32,7 @@ sqlite3_stmt *LocalDb::Prepare(const char *sql)
 
     rc = sqlite3_prepare_v2(db, sql, strlen(sql), &stmt, &tail);
     if (rc != SQLITE_OK) {
+        ReportError(rc);
         throw IOException(string("Error preparing statement: ") + sql);
     }
 
@@ -45,7 +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;
 
@@ -68,8 +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)
@@ -77,6 +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) {
@@ -92,11 +94,54 @@ void LocalDb::Open(const char *path, const char *snapshot_name,
         sqlite3_close(db);
         throw IOException("Find snapshot id");
     }
+
+    /* Create a temporary table which will be used to keep track of the objects
+     * used by this snapshot.  When the database is closed, we will summarize
+     * the results of this table into segments_used. */
+    rc = sqlite3_exec(db,
+                      "create temporary table snapshot_refs ("
+                      "    segmentid integer not null,"
+                      "    object text not null,"
+                      "    size integer not null"
+                      ")", NULL, NULL, NULL);
+    if (rc != SQLITE_OK) {
+        ReportError(rc);
+        sqlite3_close(db);
+        throw IOException("Database initialization");
+    }
+    rc = sqlite3_exec(db,
+                      "create unique index snapshot_refs_index "
+                      "on snapshot_refs(segmentid, object)",
+                      NULL, NULL, NULL);
+    if (rc != SQLITE_OK) {
+        ReportError(rc);
+        sqlite3_close(db);
+        throw IOException("Database initialization");
+    }
 }
 
 void LocalDb::Close()
 {
     int rc;
+
+    /* Summarize the snapshot_refs table into segments_used. */
+    sqlite3_stmt *stmt = Prepare("insert into segments_used "
+                                 "select ? as snapshotid, segmentid, "
+                                 "cast(used as real) / size as utilization "
+                                 "from "
+                                 "(select segmentid, sum(size) as used "
+                                 "from snapshot_refs group by segmentid) "
+                                 "join segments using (segmentid)");
+    sqlite3_bind_int64(stmt, 1, snapshotid);
+    rc = sqlite3_step(stmt);
+    if (rc != SQLITE_OK && rc != SQLITE_DONE) {
+        ReportError(rc);
+        sqlite3_close(db);
+        fprintf(stderr, "DATABASE ERROR: Unable to create segment summary!\n");
+    }
+    sqlite3_finalize(stmt);
+
+    /* Commit changes to the database and close. */
     rc = sqlite3_exec(db, "commit", NULL, NULL, NULL);
     if (rc != SQLITE_OK) {
         fprintf(stderr, "DATABASE ERROR: Can't commit database!\n");
@@ -213,6 +258,7 @@ ObjectReference LocalDb::FindObject(const string &checksum, int64_t size)
     } else if (rc == SQLITE_ROW) {
         ref = ObjectReference(IdToSegment(sqlite3_column_int64(stmt, 0)),
                               (const char *)sqlite3_column_text(stmt, 1));
+        ref.set_range(0, size);
     } else {
         fprintf(stderr, "Could not execute SELECT statement!\n");
         ReportError(rc);
@@ -260,6 +306,11 @@ bool LocalDb::IsAvailable(const ObjectReference &ref)
     sqlite3_stmt *stmt;
     bool found = false;
 
+    // Special objects (such as the zero object) aren't stored in segments, and
+    // so are always available.
+    if (!ref.is_normal())
+        return true;
+
     stmt = Prepare("select count(*) from block_index "
                    "where segmentid = ? and object = ? and expired is null");
     sqlite3_bind_int64(stmt, 1, SegmentToId(ref.get_segment()));
@@ -287,13 +338,15 @@ void LocalDb::UseObject(const ObjectReference& ref)
     int rc;
     sqlite3_stmt *stmt;
 
-    stmt = Prepare("insert or ignore into snapshot_contents "
-                   "select blockid, ? as snapshotid from block_index "
+    if (!ref.is_normal())
+        return;
+
+    stmt = Prepare("insert or ignore into snapshot_refs "
+                   "select segmentid, object, size from block_index "
                    "where segmentid = ? and object = ?");
-    sqlite3_bind_int64(stmt, 1, snapshotid);
-    sqlite3_bind_int64(stmt, 2, SegmentToId(ref.get_segment()));
+    sqlite3_bind_int64(stmt, 1, SegmentToId(ref.get_segment()));
     string obj = ref.get_sequence();
-    sqlite3_bind_text(stmt, 3, obj.c_str(), obj.size(), SQLITE_TRANSIENT);
+    sqlite3_bind_text(stmt, 2, obj.c_str(), obj.size(), SQLITE_TRANSIENT);
 
     rc = sqlite3_step(stmt);
     if (rc != SQLITE_DONE) {
@@ -311,13 +364,16 @@ void LocalDb::SetSegmentChecksum(const std::string &segment,
     int rc;
     sqlite3_stmt *stmt;
 
-    stmt = Prepare("update segments set path = ?, checksum = ? "
+    stmt = Prepare("update segments set path = ?, checksum = ?, "
+                   "size = (select sum(size) from block_index "
+                   "        where segmentid = ?) "
                    "where segmentid = ?");
     sqlite3_bind_text(stmt, 1, path.c_str(), path.size(),
                       SQLITE_TRANSIENT);
     sqlite3_bind_text(stmt, 2, checksum.c_str(), checksum.size(),
                       SQLITE_TRANSIENT);
     sqlite3_bind_int64(stmt, 3, SegmentToId(segment));
+    sqlite3_bind_int64(stmt, 4, SegmentToId(segment));
 
     rc = sqlite3_step(stmt);
     if (rc != SQLITE_DONE) {