X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=localdb.cc;h=17337f01b028d02776df674717f19d0bb1a0190a;hb=722040937d7709a7b976bf57b045dac6d703c893;hp=4683f4d83c567dca863fe42886a0a5f2ceac348b;hpb=cac644d993d130efd8d29539de6557b18c9b737e;p=cumulus.git

diff --git a/localdb.cc b/localdb.cc
index 4683f4d..17337f0 100644
--- a/localdb.cc
+++ b/localdb.cc
@@ -22,7 +22,31 @@
 
 using std::string;
 
-void LocalDb::Open(const char *path, const char *snapshot_name)
+/* Helper function to prepare a statement for execution in the current
+ * database. */
+sqlite3_stmt *LocalDb::Prepare(const char *sql)
+{
+    sqlite3_stmt *stmt;
+    int rc;
+    const char *tail;
+
+    rc = sqlite3_prepare_v2(db, sql, strlen(sql), &stmt, &tail);
+    if (rc != SQLITE_OK) {
+        ReportError(rc);
+        throw IOException(string("Error preparing statement: ") + sql);
+    }
+
+    return stmt;
+}
+
+void LocalDb::ReportError(int rc)
+{
+    fprintf(stderr, "Result code: %d\n", rc);
+    fprintf(stderr, "Error message: %s\n", sqlite3_errmsg(db));
+}
+
+void LocalDb::Open(const char *path, const char *snapshot_name,
+                   const char *snapshot_scheme, double intent)
 {
     int rc;
 
@@ -40,25 +64,25 @@ void LocalDb::Open(const char *path, const char *snapshot_name)
         throw IOException("Error starting transaction");
     }
 
+    sqlite3_extended_result_codes(db, 1);
+
     /* Insert this snapshot into the database, and determine the integer key
      * which will be used to identify it. */
-    sqlite3_stmt *stmt;
-    static const char s[] =
-        "insert into snapshots(name, timestamp) "
-        "values (?, julianday('now'))";
-    const char *tail;
-
-    rc = sqlite3_prepare_v2(db, s, strlen(s), &stmt, &tail);
-    if (rc != SQLITE_OK) {
-        sqlite3_close(db);
-        throw IOException("Error adding snapshot");
-    }
-
+    sqlite3_stmt *stmt = Prepare("insert into "
+                                 "snapshots(name, scheme, timestamp, intent) "
+                                 "values (?, ?, julianday('now'), ?)");
     sqlite3_bind_text(stmt, 1, snapshot_name, strlen(snapshot_name),
                       SQLITE_TRANSIENT);
+    if (snapshot_scheme == NULL)
+        sqlite3_bind_null(stmt, 2);
+    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) {
+        ReportError(rc);
         sqlite3_close(db);
         throw IOException("Database execution error!");
     }
@@ -66,17 +90,62 @@ void LocalDb::Open(const char *path, const char *snapshot_name)
     snapshotid = sqlite3_last_insert_rowid(db);
     sqlite3_finalize(stmt);
     if (snapshotid == 0) {
+        ReportError(rc);
         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, "Can't commit database!\n");
+        fprintf(stderr, "DATABASE ERROR: Can't commit database!\n");
+        ReportError(rc);
     }
     sqlite3_close(db);
 }
@@ -85,17 +154,9 @@ int64_t LocalDb::SegmentToId(const string &segment)
 {
     int rc;
     sqlite3_stmt *stmt;
-    static const char s1[] =
-        "insert or ignore into segments(segment) values (?);";
-    static const char s2[] =
-        "select segmentid from segments where segment = ?";
-    const char *tail;
     int64_t result;
 
-    rc = sqlite3_prepare_v2(db, s1, strlen(s1), &stmt, &tail);
-    if (rc != SQLITE_OK) {
-        throw IOException("Find id by segment name");
-    }
+    stmt = Prepare("insert or ignore into segments(segment) values (?)");
     sqlite3_bind_text(stmt, 1, segment.c_str(), segment.size(),
                       SQLITE_TRANSIENT);
     rc = sqlite3_step(stmt);
@@ -104,11 +165,7 @@ int64_t LocalDb::SegmentToId(const string &segment)
     }
     sqlite3_finalize(stmt);
 
-    rc = sqlite3_prepare_v2(db, s2, strlen(s2), &stmt, &tail);
-    if (rc != SQLITE_OK) {
-        throw IOException("Find id by segment name");
-    }
-
+    stmt = Prepare("select segmentid from segments where segment = ?");
     sqlite3_bind_text(stmt, 1, segment.c_str(), segment.size(),
                       SQLITE_TRANSIENT);
 
@@ -130,16 +187,9 @@ string LocalDb::IdToSegment(int64_t segmentid)
 {
     int rc;
     sqlite3_stmt *stmt;
-    static const char s[] =
-        "select segment from segments where segmentid = ?";
-    const char *tail;
     string result;
 
-    rc = sqlite3_prepare_v2(db, s, strlen(s), &stmt, &tail);
-    if (rc != SQLITE_OK) {
-        throw IOException("Find segment by id");
-    }
-
+    stmt = Prepare("select segment from segments where segmentid = ?");
     sqlite3_bind_int64(stmt, 1, segmentid);
 
     rc = sqlite3_step(stmt);
@@ -157,19 +207,20 @@ string LocalDb::IdToSegment(int64_t segmentid)
 }
 
 void LocalDb::StoreObject(const ObjectReference& ref,
-                          const string &checksum, int64_t size)
+                          const string &checksum, int64_t size,
+                          double age)
 {
     int rc;
     sqlite3_stmt *stmt;
-    static const char s[] =
-        "insert into "
-        "block_index(segmentid, object, checksum, size, timestamp) "
-        "values (?, ?, ?, ?, julianday('now'))";
-    const char *tail;
 
-    rc = sqlite3_prepare_v2(db, s, strlen(s), &stmt, &tail);
-    if (rc != SQLITE_OK) {
-        return;
+    if (age == 0.0) {
+        stmt = Prepare("insert into block_index("
+                       "segmentid, object, checksum, size, timestamp) "
+                       "values (?, ?, ?, ?, julianday('now'))");
+    } else {
+        stmt = Prepare("insert into block_index("
+                       "segmentid, object, checksum, size, timestamp) "
+                       "values (?, ?, ?, ?, ?)");
     }
 
     sqlite3_bind_int64(stmt, 1, SegmentToId(ref.get_segment()));
@@ -178,10 +229,13 @@ void LocalDb::StoreObject(const ObjectReference& ref,
     sqlite3_bind_text(stmt, 3, checksum.c_str(), checksum.size(),
                       SQLITE_TRANSIENT);
     sqlite3_bind_int64(stmt, 4, size);
+    if (age != 0.0)
+        sqlite3_bind_double(stmt, 5, age);
 
     rc = sqlite3_step(stmt);
     if (rc != SQLITE_DONE) {
         fprintf(stderr, "Could not execute INSERT statement!\n");
+        ReportError(rc);
     }
 
     sqlite3_finalize(stmt);
@@ -191,18 +245,10 @@ ObjectReference LocalDb::FindObject(const string &checksum, int64_t size)
 {
     int rc;
     sqlite3_stmt *stmt;
-    static const char s[] =
-        "select segmentid, object from block_index "
-        "where checksum = ? and size = ? and expired is null";
-    const char *tail;
-
     ObjectReference ref;
 
-    rc = sqlite3_prepare_v2(db, s, strlen(s), &stmt, &tail);
-    if (rc != SQLITE_OK) {
-        return ref;
-    }
-
+    stmt = Prepare("select segmentid, object from block_index "
+                   "where checksum = ? and size = ? and expired is null");
     sqlite3_bind_text(stmt, 1, checksum.c_str(), checksum.size(),
                       SQLITE_TRANSIENT);
     sqlite3_bind_int64(stmt, 2, size);
@@ -212,8 +258,10 @@ 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);
     }
 
     sqlite3_finalize(stmt);
@@ -221,22 +269,15 @@ ObjectReference LocalDb::FindObject(const string &checksum, int64_t size)
     return ref;
 }
 
-bool LocalDb::IsOldObject(const string &checksum, int64_t size)
+bool LocalDb::IsOldObject(const string &checksum, int64_t size, double *age,
+                          int *group)
 {
     int rc;
     sqlite3_stmt *stmt;
-    static const char s[] =
-        "select segmentid, object from block_index "
-        "where checksum = ? and size = ?";
-    const char *tail;
-
     bool found = false;
 
-    rc = sqlite3_prepare_v2(db, s, strlen(s), &stmt, &tail);
-    if (rc != SQLITE_OK) {
-        return false;
-    }
-
+    stmt = Prepare("select segmentid, object, timestamp, expired "
+                   "from block_index where checksum = ? and size = ?");
     sqlite3_bind_text(stmt, 1, checksum.c_str(), checksum.size(),
                       SQLITE_TRANSIENT);
     sqlite3_bind_int64(stmt, 2, size);
@@ -246,8 +287,45 @@ bool LocalDb::IsOldObject(const string &checksum, int64_t size)
         found = false;
     } else if (rc == SQLITE_ROW) {
         found = true;
+        *age = sqlite3_column_double(stmt, 2);
+        *group = sqlite3_column_int(stmt, 3);
     } else {
         fprintf(stderr, "Could not execute SELECT statement!\n");
+        ReportError(rc);
+    }
+
+    sqlite3_finalize(stmt);
+
+    return found;
+}
+
+/* Does this object still exist in the database (and not expired)? */
+bool LocalDb::IsAvailable(const ObjectReference &ref)
+{
+    int rc;
+    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()));
+    sqlite3_bind_text(stmt, 2, ref.get_sequence().c_str(),
+                      ref.get_sequence().size(), SQLITE_TRANSIENT);
+
+    rc = sqlite3_step(stmt);
+    if (rc == SQLITE_DONE) {
+        found = false;
+    } else if (rc == SQLITE_ROW) {
+        if (sqlite3_column_int(stmt, 0) > 0)
+            found = true;
+    } else {
+        fprintf(stderr, "Could not execute SELECT statement!\n");
+        ReportError(rc);
     }
 
     sqlite3_finalize(stmt);
@@ -259,26 +337,89 @@ void LocalDb::UseObject(const ObjectReference& ref)
 {
     int rc;
     sqlite3_stmt *stmt;
-    static const char s[] =
-        "insert or ignore into snapshot_contents "
-        "select blockid, ? as snapshotid from block_index "
-        "where segmentid = ? and object = ?";
-    const char *tail;
 
-    rc = sqlite3_prepare_v2(db, s, strlen(s), &stmt, &tail);
-    if (rc != SQLITE_OK) {
+    if (!ref.is_normal())
         return;
-    }
 
-    sqlite3_bind_int64(stmt, 1, snapshotid);
-    sqlite3_bind_int64(stmt, 2, SegmentToId(ref.get_segment()));
+    stmt = Prepare("insert or ignore into snapshot_refs "
+                   "select segmentid, object, size from block_index "
+                   "where segmentid = ? and object = ?");
+    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) {
         fprintf(stderr, "Could not execute INSERT statement!\n");
+        ReportError(rc);
+    }
+
+    sqlite3_finalize(stmt);
+}
+
+void LocalDb::SetSegmentChecksum(const std::string &segment,
+                                 const std::string &path,
+                                 const std::string &checksum)
+{
+    int rc;
+    sqlite3_stmt *stmt;
+
+    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) {
+        fprintf(stderr, "Could not update segment checksum in database!\n");
+        ReportError(rc);
+    }
+
+    sqlite3_finalize(stmt);
+}
+
+bool LocalDb::GetSegmentChecksum(const string &segment,
+                                 string *seg_path,
+                                 string *seg_checksum)
+{
+    int rc;
+    sqlite3_stmt *stmt;
+    ObjectReference ref;
+    int found = false;
+
+    stmt = Prepare("select path, checksum from segments where segment = ?");
+    sqlite3_bind_text(stmt, 1, segment.c_str(), segment.size(),
+                      SQLITE_TRANSIENT);
+
+    rc = sqlite3_step(stmt);
+    if (rc == SQLITE_DONE) {
+    } else if (rc == SQLITE_ROW) {
+        found = true;
+        const char *val;
+
+        val = (const char *)sqlite3_column_text(stmt, 0);
+        if (val == NULL)
+            found = false;
+        else
+            *seg_path = val;
+
+        val = (const char *)sqlite3_column_text(stmt, 1);
+        if (val == NULL)
+            found = false;
+        else
+            *seg_checksum = val;
+    } else {
+        fprintf(stderr, "Could not execute SELECT statement!\n");
+        ReportError(rc);
     }
 
     sqlite3_finalize(stmt);
+
+    return found;
 }