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authorAndré Nusser <andre.nusser@googlemail.com>2020-02-17 11:40:59 +0100
committerAndré Nusser <andre.nusser@googlemail.com>2020-02-23 13:46:28 +0100
commitc318eef97ac2b3854e8f5c6bae1dd518231556f6 (patch)
tree970194089af5b78f986c61d949116a669fd7b6f9 /src/events_ds.h
parentd7446df11d14f2d83d2d3313f918a434373a63e9 (diff)
Work in review for EventsDS.
Diffstat (limited to 'src/events_ds.h')
-rw-r--r--src/events_ds.h57
1 files changed, 40 insertions, 17 deletions
diff --git a/src/events_ds.h b/src/events_ds.h
index 1b3a4b6..6d2959e 100644
--- a/src/events_ds.h
+++ b/src/events_ds.h
@@ -38,35 +38,53 @@
#include "range.h"
#include "instrument.h"
-//! TODO: document class as a whole
-//! TODO: What s does DS stand for?
-// TODO: make it possible to choose sizes
+//! EventsDS (events data structure) is the central engine events data structure.
+//! It enables the following fast operations:
+//! * Add a new event
+//! * Remove an event
+//! * Iterate over all events of a channel
+//! * Get all events of a certain group
+//! * ...
+//!
+//! All operations are constant time (assuming bounded group sizes). Also, it
+//! assignes the event ids and group ids. Certain functions may be specific to certain event types.
+//!
+//! This data structure makes several assumptions about its usage:
+//! * we assume that we add a group in one batch without deleting anything in-between
+//! * we assume that an event_id isn't used after remove(event_id) was called
+//! * we assume that before starting to emplace a new group, startAddingNewGroup is called
+
+// TODO: make it possible to choose sizes of all the containers on initialization
+// such that we avoid allocations all together as long as we stay in these bounds.
+
class EventsDS
{
public:
- EventsDS() = default; // TODO: Is this needed?
-
- //! TODO: document all the (public) things!
+ //! Adds a new event of type T (via emplace syntax) to the data structure.
template <typename T, typename... Args>
T& emplace(int ch, Args&&... args);
- //! TODO: document all the (public) things!
+ //! Removes the event with id being event_id.
void remove(EventID event_id);
- //! TODO: document all the (public) things!
+ //! Returns the number of all events of a certain channel.
std::size_t numberOfEvents(int ch) const;
- //! TODO: document all the (public) things!
+ //! Gives a range that can be used in a range based for loop to iterate over
+ //! all events in channel ch of type T.
template <typename T>
ContainerRange<std::vector<T>> iterateOver(int ch);
- //! TODO: document all the (public) things!
+ //! Returns all the group ids of sample events associated with instrument_id.
const EventGroupIDs& getSampleEventGroupIDsOf(InstrumentID instrument_id) const;
- //! TODO: document all the (public) things!
+ //! Get all the event ids of events that are in the group with event_group_id.
const EventIDs& getEventIDsOf(EventGroupID event_group_id) const;
- //! TODO: document all the (public) things!
+ //! This function should always be called before we emplace a new batch of
+ //! events. This internally creates a new group id and then assigns this group
+ //! id to all the events that are emplaced afterwards. The group id changes,
+ //! when startAddingNewGroup is again called.
void startAddingNewGroup(InstrumentID instrument_id = InstrumentID());
private:
@@ -90,7 +108,9 @@ private:
struct GroupData
{
EventIDs event_ids;
- Event::Type type;
+ // Note: In the future, we could make groups just consist of events of one type.
+ // Currently that is not necessary, but untested.
+ // Event::Type type;
// SampleEvent specific data
std::size_t instrument_index;
@@ -102,8 +122,7 @@ private:
MemoryHeap<GroupData> id_to_group_data;
// SampleEvent specific data
- // TODO: maybe use something that actually has the size of the number of instruments
- // Also, can we guarantee that there are at most 128 instrument ids?
+ // TODO: Make this into a vector and always have the size be the number of instruments.
std::array<EventGroupIDs, 128> instruments_sample_event_group_ids;
EventGroupID current_group_id;
@@ -115,6 +134,9 @@ private:
template <typename T, typename... Args>
T& EventsDS::emplace(int ch, Args&&... args)
{
+ // add new event types here
+ static_assert(std::is_same<T, SampleEvent>::value);
+
if (std::is_same<T, SampleEvent>::value)
{
auto& sample_events = channel_data_array[ch].sample_events;
@@ -131,13 +153,14 @@ T& EventsDS::emplace(int ch, Args&&... args)
return sample_event;
}
-
- assert(false); // TODO: This should probably be a static_assert instead?
}
template <typename T>
ContainerRange<std::vector<T>> EventsDS::iterateOver(int ch)
{
+ // add new event types here
+ static_assert(std::is_same<T, SampleEvent>::value);
+
if (std::is_same<T, SampleEvent>::value)
{
auto& sample_events = channel_data_array[ch].sample_events;