armem/dev => master

source/RobotAPI/interface/armem/query.ice

@@ -49,6 +49,57 @@ module armarx
                         long first = 0;  ///< First index to get.
                         long last = -1;  ///< Last index to get (inclusive).
                     };
+
+
+                    /**
+                     * @brief Get snapshot(s) around timestamp.
+                     *
+                     * If there is a snapshot which exactly matches the query timestamp,
+                     * the behavior is as for the @see Single query. 
+                     * 
+                     * However, if there is no matching timestamp, the snapshots before 
+                     * and after the query timestamp will be returned.
+                     * 
+                     * If #eps is positive, the snapshots must be within the time
+                     * range [timestamp - eps, timestamp + eps]. 
+                     * Consequently, the query result can be empty.
+                     *
+                     * Hint: 
+                     *   This query can be quite useful when interpolating snapshots
+                     *   is possible.
+                     */
+                    class TimeApprox extends EntityQuery
+                    {
+                        long timestamp = -1;
+                        long eps = -1;
+                    };
+
+                    /**
+                     * @brief Get the last snapshot before or at the timestamp.
+                     * 
+                     * This query is kind of similar to latest() but with a reference timestamp.
+                     * 
+                     */
+                    class BeforeOrAtTime extends EntityQuery
+                    {
+                        long timestamp;
+                    }
+
+                    /**
+                     * @brief Get the last snapshot before the timestamp or a sequence of 
+                     *           n last elements before the timestamp depending on #maxEntries
+                     * 
+                     * Depending on #maxEntries, the behavior is as follows:
+                     *  - #maxEntries == 1 => last element before timestamp
+                     *  - #maxEntries > 1  => n last elements before timestamp
+                     *  - #maxEntries < 0  => all elements before timestamp
+                     */
+                    class BeforeTime extends EntityQuery
+                    {
+                        long timestamp;
+                        long maxEntries = 1;
+                    }
+
                 }