CacheMemory.cpp
Go to the documentation of this file.
/**
* @file
* @brief Source file for Cache class
* @author Jonathan Thomas <jonathan@openshot.org>
*
* @ref License
*/
/* LICENSE
*
* Copyright (c) 2008-2019 OpenShot Studios, LLC
* <http://www.openshotstudios.com/>. This file is part of
* OpenShot Library (libopenshot), an open-source project dedicated to
* delivering high quality video editing and animation solutions to the
* world. For more information visit <http://www.openshot.org/>.
*
* OpenShot Library (libopenshot) is free software: you can redistribute it
* and/or modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* OpenShot Library (libopenshot) is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "../include/CacheMemory.h"
using namespace std;
using namespace openshot;
// Default constructor, no max bytes
CacheMemory::CacheMemory() : CacheBase(0) {
// Set cache type name
cache_type = "CacheMemory";
range_version = 0;
needs_range_processing = false;
}
// Constructor that sets the max bytes to cache
CacheMemory::CacheMemory(int64_t max_bytes) : CacheBase(max_bytes) {
// Set cache type name
cache_type = "CacheMemory";
range_version = 0;
needs_range_processing = false;
}
// Default destructor
CacheMemory::~CacheMemory()
{
frames.clear();
frame_numbers.clear();
ordered_frame_numbers.clear();
// remove critical section
delete cacheCriticalSection;
cacheCriticalSection = NULL;
}
// Calculate ranges of frames
void CacheMemory::CalculateRanges() {
// Only calculate when something has changed
if (needs_range_processing) {
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
// Sort ordered frame #s, and calculate JSON ranges
std::sort(ordered_frame_numbers.begin(), ordered_frame_numbers.end());
// Clear existing JSON variable
Json::Value ranges = Json::Value(Json::arrayValue);
// Increment range version
range_version++;
std::vector<int64_t>::iterator itr_ordered;
int64_t starting_frame = *ordered_frame_numbers.begin();
int64_t ending_frame = *ordered_frame_numbers.begin();
// Loop through all known frames (in sequential order)
for (itr_ordered = ordered_frame_numbers.begin(); itr_ordered != ordered_frame_numbers.end(); ++itr_ordered) {
int64_t frame_number = *itr_ordered;
if (frame_number - ending_frame > 1) {
// End of range detected
Json::Value range;
// Add JSON object with start/end attributes
// Use strings, since int64_ts are supported in JSON
range["start"] = std::to_string(starting_frame);
range["end"] = std::to_string(ending_frame);
ranges.append(range);
// Set new starting range
starting_frame = frame_number;
}
// Set current frame as end of range, and keep looping
ending_frame = frame_number;
}
// APPEND FINAL VALUE
Json::Value range;
// Add JSON object with start/end attributes
// Use strings, since int64_ts are not supported in JSON
range["start"] = std::to_string(starting_frame);
range["end"] = std::to_string(ending_frame);
ranges.append(range);
// Cache range JSON as string
json_ranges = ranges.toStyledString();
// Reset needs_range_processing
needs_range_processing = false;
}
}
// Add a Frame to the cache
void CacheMemory::Add(std::shared_ptr<Frame> frame)
{
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
int64_t frame_number = frame->number;
// Freshen frame if it already exists
if (frames.count(frame_number))
// Move frame to front of queue
MoveToFront(frame_number);
else
{
// Add frame to queue and map
frames[frame_number] = frame;
frame_numbers.push_front(frame_number);
ordered_frame_numbers.push_back(frame_number);
needs_range_processing = true;
// Clean up old frames
CleanUp();
}
}
// Get a frame from the cache (or NULL shared_ptr if no frame is found)
std::shared_ptr<Frame> CacheMemory::GetFrame(int64_t frame_number)
{
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
// Does frame exists in cache?
if (frames.count(frame_number))
// return the Frame object
return frames[frame_number];
else
// no Frame found
return std::shared_ptr<Frame>();
}
// Get the smallest frame number (or NULL shared_ptr if no frame is found)
std::shared_ptr<Frame> CacheMemory::GetSmallestFrame()
{
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
std::shared_ptr<openshot::Frame> f;
// Loop through frame numbers
std::deque<int64_t>::iterator itr;
int64_t smallest_frame = -1;
for(itr = frame_numbers.begin(); itr != frame_numbers.end(); ++itr)
{
if (*itr < smallest_frame || smallest_frame == -1)
smallest_frame = *itr;
}
// Return frame
f = GetFrame(smallest_frame);
return f;
}
// Gets the maximum bytes value
int64_t CacheMemory::GetBytes()
{
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
int64_t total_bytes = 0;
// Loop through frames, and calculate total bytes
std::deque<int64_t>::reverse_iterator itr;
for(itr = frame_numbers.rbegin(); itr != frame_numbers.rend(); ++itr)
{
total_bytes += frames[*itr]->GetBytes();
}
return total_bytes;
}
// Remove a specific frame
void CacheMemory::Remove(int64_t frame_number)
{
Remove(frame_number, frame_number);
}
// Remove range of frames
void CacheMemory::Remove(int64_t start_frame_number, int64_t end_frame_number)
{
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
// Loop through frame numbers
std::deque<int64_t>::iterator itr;
for(itr = frame_numbers.begin(); itr != frame_numbers.end();)
{
if (*itr >= start_frame_number && *itr <= end_frame_number)
{
// erase frame number
itr = frame_numbers.erase(itr);
}else
itr++;
}
// Loop through ordered frame numbers
std::vector<int64_t>::iterator itr_ordered;
for(itr_ordered = ordered_frame_numbers.begin(); itr_ordered != ordered_frame_numbers.end();)
{
if (*itr_ordered >= start_frame_number && *itr_ordered <= end_frame_number)
{
// erase frame number
frames.erase(*itr_ordered);
itr_ordered = ordered_frame_numbers.erase(itr_ordered);
}else
itr_ordered++;
}
// Needs range processing (since cache has changed)
needs_range_processing = true;
}
// Move frame to front of queue (so it lasts longer)
void CacheMemory::MoveToFront(int64_t frame_number)
{
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
// Does frame exists in cache?
if (frames.count(frame_number))
{
// Loop through frame numbers
std::deque<int64_t>::iterator itr;
for(itr = frame_numbers.begin(); itr != frame_numbers.end(); ++itr)
{
if (*itr == frame_number)
{
// erase frame number
frame_numbers.erase(itr);
// add frame number to 'front' of queue
frame_numbers.push_front(frame_number);
break;
}
}
}
}
// Clear the cache of all frames
void CacheMemory::Clear()
{
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
frames.clear();
frame_numbers.clear();
ordered_frame_numbers.clear();
needs_range_processing = true;
}
// Count the frames in the queue
int64_t CacheMemory::Count()
{
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
// Return the number of frames in the cache
return frames.size();
}
// Clean up cached frames that exceed the number in our max_bytes variable
void CacheMemory::CleanUp()
{
// Do we auto clean up?
if (max_bytes > 0)
{
// Create a scoped lock, to protect the cache from multiple threads
const GenericScopedLock<CriticalSection> lock(*cacheCriticalSection);
while (GetBytes() > max_bytes && frame_numbers.size() > 20)
{
// Get the oldest frame number.
int64_t frame_to_remove = frame_numbers.back();
// Remove frame_number and frame
Remove(frame_to_remove);
}
}
}
// Generate JSON string of this object
std::string CacheMemory::Json() {
// Return formatted string
return JsonValue().toStyledString();
}
// Generate Json::Value for this object
Json::Value CacheMemory::JsonValue() {
// Process range data (if anything has changed)
CalculateRanges();
// Create root json object
Json::Value root = CacheBase::JsonValue(); // get parent properties
root["type"] = cache_type;
root["version"] = std::to_string(range_version);
// Parse and append range data (if any)
try {
const Json::Value ranges = openshot::stringToJson(json_ranges);
root["ranges"] = ranges;
} catch (...) { }
// return JsonValue
return root;
}
// Load JSON string into this object
void CacheMemory::SetJson(const std::string value) {
try
{
// Parse string to Json::Value
const Json::Value root = openshot::stringToJson(value);
// Set all values that match
SetJsonValue(root);
}
catch (const std::exception& e)
{
// Error parsing JSON (or missing keys)
throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
}
}
// Load Json::Value into this object
void CacheMemory::SetJsonValue(const Json::Value root) {
// Close timeline before we do anything (this also removes all open and closing clips)
Clear();
// Set parent data
CacheBase::SetJsonValue(root);
if (!root["type"].isNull())
cache_type = root["type"].asString();
}
openshot::CacheBase
All cache managers in libopenshot are based on this CacheBase class.
Definition: CacheBase.h:50
openshot::CacheBase::JsonValue
virtual Json::Value JsonValue()=0
Generate Json::Value for this object.
Definition: CacheBase.cpp:57
openshot::CacheBase::cache_type
std::string cache_type
This is a friendly type name of the derived cache instance.
Definition: CacheBase.h:52
openshot::CacheBase::SetJsonValue
virtual void SetJsonValue(const Json::Value root)=0
Load Json::Value into this object.
Definition: CacheBase.cpp:70
openshot::CacheBase::cacheCriticalSection
juce::CriticalSection * cacheCriticalSection
Section lock for multiple threads.
Definition: CacheBase.h:56
openshot::CacheBase::max_bytes
int64_t max_bytes
This is the max number of bytes to cache (0 = no limit)
Definition: CacheBase.h:53
openshot::CacheMemory::CacheMemory
CacheMemory()
Default constructor, no max bytes.
Definition: CacheMemory.cpp:37
openshot::CacheMemory::Count
int64_t Count()
Count the frames in the queue.
Definition: CacheMemory.cpp:285
openshot::CacheMemory::Add
void Add(std::shared_ptr< openshot::Frame > frame)
Add a Frame to the cache.
Definition: CacheMemory.cpp:125
openshot::CacheMemory::SetJson
void SetJson(const std::string value)
Load JSON string into this object.
Definition: CacheMemory.cpp:345
openshot::CacheMemory::GetBytes
int64_t GetBytes()
Gets the maximum bytes value.
Definition: CacheMemory.cpp:188
openshot::CacheMemory::~CacheMemory
virtual ~CacheMemory()
Definition: CacheMemory.cpp:53
openshot::CacheMemory::Json
std::string Json()
Get and Set JSON methods.
Definition: CacheMemory.cpp:316
openshot::CacheMemory::GetFrame
std::shared_ptr< openshot::Frame > GetFrame(int64_t frame_number)
Get a frame from the cache.
Definition: CacheMemory.cpp:150
openshot::CacheMemory::SetJsonValue
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: CacheMemory.cpp:362
openshot::CacheMemory::MoveToFront
void MoveToFront(int64_t frame_number)
Move frame to front of queue (so it lasts longer)
Definition: CacheMemory.cpp:247
openshot::CacheMemory::Remove
void Remove(int64_t frame_number)
Remove a specific frame.
Definition: CacheMemory.cpp:206
openshot::CacheMemory::Clear
void Clear()
Clear the cache of all frames.
Definition: CacheMemory.cpp:273
openshot::CacheMemory::JsonValue
Json::Value JsonValue()
Generate Json::Value for this object.
Definition: CacheMemory.cpp:323
openshot::CacheMemory::GetSmallestFrame
std::shared_ptr< openshot::Frame > GetSmallestFrame()
Get the smallest frame number.
Definition: CacheMemory.cpp:166
openshot::InvalidJSON
Exception for invalid JSON.
Definition: Exceptions.h:206
openshot
This namespace is the default namespace for all code in the openshot library.
Definition: AudioBufferSource.h:39
openshot::stringToJson
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:33