I am trying to write a function to search a linked list for an element, but when I try compiling it I get an error saying cannot convert list to node* in assignment. Why is that happening? Isn't my list a node* already?
Code:
#include <iostream>
#include <stdio.h>
using namespace std;
struct node {
int data;
node * next;
};
class list {
public:
list();
void createnode(int value);
int size();
void insert_position(int pos, int value);
void delete_first();
void delete_last();
void remove(int pos);
int get(int pos);
int search(int searchNum);
node * head, * tail;
};
list::list() {
head = NULL;
tail = NULL;
}
node * search(list l, int value) {
node * p;
for (p = l; p != nullptr; p = p - > next) {
if (p - > data == value) return p;
}
return nullptr;
}
No your list is not a node*. list is just a class.
What you are doing is assigning a class object to node*.
node * search(node* l, int value) {
node * p;
for (p = l; p != NULL; p = p -> next) {
if (p -> data == value) return p;
}
return NULL;
}
Related
I'm new to c++ and I have to work with dynamic arrays:| I need to define a few dynamic arrays inside my header file and access them from main. The problem is that when I'm defining the arrays inside the structs, I get segmentation faults and don't know how to fix them.
Below is my header file.
I'm aware that there are lots of problems with my code and I could use your help. I'm really stuck here.
Thanks in advance.
I expect this code to work fine with dynamic arrays just like it does with vectors. But it's not.
`
#pragma once
#include <iostream>
#include <functional>
#include <algorithm>
#define children_link_Size 149
#define row 15
#define col 100
using namespace std;
int itemListIndex = 0;
int freqIdx = 0;
int childIdx = 0;
int linkIdx = 0;
namespace std {
template <typename T> T* begin(std::pair<T*, T*> const& p)
{
return p.first;
}
template <typename T> T* end(std::pair<T*, T*> const& p)
{
return p.second;
}
}
struct Node
{
int itemValue{};
int order{ 0 };
int freq{ 0 };
Node* parent{ nullptr };
Node* children{};
Node* links{};
Node() {
children = new Node[children_link_Size];
links = new Node[children_link_Size];
}
explicit Node(int const& p_value, int p_order = 0) :itemValue(p_value), order(p_order)
{
++freq;
cout << " + " << itemValue << " (" << order << ")" << endl;
}
bool operator ==(Node const& p_node) const
{
return itemValue == p_node.itemValue;
}
~Node() {
delete[] children;
delete[] links;
}
};
/*struct mySet {
Node* OrderedItems;
mySet()
{
OrderedItems = new Node[uniqueSize];
}
void insert(Node item)
{
for (int i = 0; i < uniqueSize; i++)
{
for (int j = 0; j < i; j++)
{
if (item == OrderedItems[j])
{
break;
}
else
{
OrderedItems[i] = item;
}
}
}
}
~mySet()
{
delete[] OrderedItems;
}
};*/
struct ItemSupport
{
explicit ItemSupport(int p_minSup) { ItemSupport::minSup = p_minSup; }
Node* Itemset = new (nothrow) Node[row];
Node* OrderedItems = new (nothrow) Node[row];
ItemSupport& operator<<(int const& p_itemValue)
{
static int order = 0;
auto inode = find_if(Itemset, Itemset + row, [&p_itemValue](Node const& p_node)
{
return p_node.itemValue == p_itemValue;
});
if (inode == Itemset + row)
{
Node node(p_itemValue, order);
Itemset[itemListIndex] = node;
itemListIndex++;
++order;
}
else
{
auto& node = (*inode);
++node.freq;
}
return *this;
}
friend ostream& operator<<(ostream& p_os, ItemSupport const& p_itemSupport)
{
ItemSupport* NoDe = {0};
if (NoDe)
{
NoDe->OrderedItems = p_itemSupport.getFrequentItems();
for (Node node : std::make_pair(NoDe->OrderedItems, NoDe->OrderedItems + row))
{
p_os << node.itemValue << ": support " << node.freq << ", order " << node.order << endl;
}
return p_os;
}
}
Node* getItem(int const& p_itemValue)
{
auto inode = find_if(Itemset, Itemset + row, [&p_itemValue](Node const& p_node)
{
return p_node.itemValue == p_itemValue;
});
if (inode != Itemset + row)
{
Node* node = const_cast<Node*>(&(*inode));
return node;
}
return nullptr;
}
static int getMinSup()
{
return minSup;
}
static int minSup;
private:
Node* getFrequentItems() const
{
int j = 0;
for (int i = 0; i < row; i++)
{
if (Itemset[i].freq >= minSup)
OrderedItems[j++] = Itemset[i];
}
return OrderedItems;
}
Node* getUnfrequentItems() const
{
int j = 0;
for (int i = 0; i < row; i++)
{
if (Itemset[i].freq <= minSup)
OrderedItems[j++] = Itemset[i];
}
return OrderedItems;
}
/*~ItemSupport() {
//delete[] Itemset;
//delete[] OrderedItems;
}*/
};
int ItemSupport::minSup = 0;
struct FP_Tree
{
explicit FP_Tree(ItemSupport& p_itemSupport, const int& p_rootValue = int()) :_headItemSupport(p_itemSupport)
{
_root = new Node(p_rootValue);
}
//void construct(Transaction const& p_itemValues)
void construct(int *p_itemValues)
{
// A. Order items into transaction
ItemSupport* ordered = {0};
for (int const& itemValue : std::make_pair(p_itemValues, p_itemValues + row))
{
Node* pNode = _headItemSupport.getItem(itemValue);
if (pNode && pNode->freq >= ItemSupport::getMinSup())
{
if (ordered)
{
ordered->OrderedItems[freqIdx] = *pNode;
freqIdx++;
}
}
}
// B. Create FP_TREE
Node* actualNode = _root;
bool here = true;
string tab;
if (ordered)
{
for (Node const& node : std::make_pair(ordered->OrderedItems, ordered->OrderedItems + row))
{
tab += "\t-";
auto it = actualNode->children;
if (here)
{
auto it = find_if(actualNode->children,
actualNode->children + children_link_Size,
[&node](Node const& nodeTmp) {
return node == (nodeTmp);
});
here &= it != actualNode->children + children_link_Size;
}
if (here)
{
actualNode = it;
++actualNode->freq;
}
else
{
Node* pNode = new Node(node.itemValue);
actualNode->children[childIdx++] = *pNode;
pNode->parent = actualNode;
Node* pNodeHead = _headItemSupport.getItem(node.itemValue);
pNodeHead->links[linkIdx++] = *pNode;
actualNode = pNode;
delete pNode;
}
//cout << tab << actualNode->_itemValue << "(" << actualNode->_freq << ")" << endl;
}
}
//cout << endl;
}
ItemSupport& headItemSupport() const
{
return _headItemSupport;
}
public:
Node* root() const
{
return _root;
}
private:
ItemSupport& _headItemSupport;
Node* _root;
};
`
I expect this code to work fine with dynamic arrays just like it does with vectors
Since you are using C++, do use std::vector -- it will save you a lot of trouble and there is no reason not to.
Given an infinite stream of characters and a list L of strings, create a function that calls an external API when a word in L is recognized during the processing of the stream.
Example:
L = ["ok","test","one","try","trying"]
stream = a,b,c,o,k,d,e,f,t,r,y,i,n,g.............
The call to external API will happen when 'k' is encountered, again when the 'y' is encountered, and again at 'g'.
My idea:
Create trie out of the list and navigate the nodes as you read from stream in linear time. But there would be a bug if you just do simple trie search.
Assume you have words "abxyz" and "xyw" and your input is "abxyw".In this case you can't recognize "xyw" with trie.
So search should be modified as below:
let's take above use case "abxyw". We start the search and we find we have all the element till 'x'. Moment you get 'x' you have two options:
Check if the current element is equal to the head of trie and if it is equal to head of trie then call recursive search.
Continue till the end of current word. In this case for your given input it will return false but for the recursive search we started in point 1, it will return true.
Below is my modified search but I think it has bugs and can be improved. Any suggestions?
#define SIZE 26
struct tri{
int complete;
struct tri *child[SIZE];
};
void insert(char *c, struct tri **t)
{
struct tri *current = *t;
while(*c != '\0')
{
int i;
int letter = *c - 'a';
if(current->child[letter] == NULL) {
current->child[letter] = malloc(sizeof(*current));
memset(current->child[letter], 0, sizeof(struct tri));
}
current = current->child[letter];
c++;
}
current->complete = 1;
}
struct tri *t;
int flag = 0;
int found(char *c, struct tri *tt)
{
struct tri *current = tt;
if (current == NULL)
return 0;
while(*c != '\0')
{
int i;
int letter = *c - 'a';
/* if this is the first char then recurse from begining*/
if (t->child[letter] != NULL)
flag = found(c+1, t->child[letter]);
if (flag == 1)
return 1;
if(!flag && current->child[letter] == NULL) {
return 0;
}
current = current->child[letter];
c++;
}
return current->complete;
}
int main()
{
int i;
t = malloc(sizeof(*t));
t->complete = 0;
memset(t, 0, sizeof(struct tri));
insert("weathez", &t);
insert("eather", &t);
insert("weather", &t);
(1 ==found("weather", t))?printf("found\n"):printf("not found\n");
return 0;
}
What you want to do is exactly what Aho-Corasick algorithm does.
You can take a look at my Aho-Corasick implementation. It's contest-oriented, so maybe not focused on readability but I think it's quite clear:
typedef vector<int> VI;
struct Node {
int size;
Node *fail, *output;
VI id;
map<char, Node*> next;
};
typedef pair<Node*, Node*> P;
typedef map<char, Node*> MCP;
Node* root;
inline void init() {
root = new Node;
root->size = 0;
root->output = root->fail = NULL;
}
Node* add(string& s, int u, int c = 0, Node* p = root) {
if (p == NULL) {
p = new Node;
p->size = c;
p->fail = p->output = NULL;
}
if (c == s.size()) p->id.push_back(u);
else {
if (not p->next.count(s[c])) p->next[s[c]] = NULL;
p->next[s[c]] = add(s, u, c + 1, p->next[s[c]]);
}
return p;
}
void fill_fail_output() {
queue<pair<char, P> > Q;
for (MCP::iterator it=root->next.begin();
it!=root->next.end();++it)
Q.push(pair<char, P> (it->first, P(root, it->second)));
while (not Q.empty()) {
Node *pare = Q.front().second.first;
Node *fill = Q.front().second.second;
char c = Q.front().first; Q.pop();
while (pare != root && !pare->fail->next.count(c))
pare=pare->fail;
if (pare == root) fill->fail = root;
else fill->fail = pare->fail->next[c];
if (fill->fail->id.size() != 0)
fill->output = fill->fail;
else fill->output = fill->fail->output;
for (MCP::iterator it=fill->next.begin();
it!=fill->next.end();++it)
Q.push(pair<char,P>(it->first,P(fill,it->second)));
}
}
void match(int c, VI& id) {
for (int i = 0; i < id.size(); ++i) {
cout << "Matching of pattern " << id[i];
cout << " ended at " << c << endl;
}
}
void search(string& s) {
int i = 0, j = 0;
Node *p = root, *q;
while (j < s.size()) {
while (p->next.count(s[j])) {
p = p->next[s[j++]];
if (p->id.size() != 0) match(j - 1, p->id);
q = p->output;
while (q != NULL) {
match(j - 1, q->id);
q = q->output;
}
}
if (p != root) {
p = p->fail;
i = j - p->size;
}
else i = ++j;
}
}
void erase(Node* p = root) {
for (MCP::iterator it = p->next.begin();
it != p->next.end(); ++it)
erase(it->second);
delete p;
}
int main() {
init();
int n;
cin >> n;
for (int i = 0; i < n; ++i) {
string s;
cin >> s;
add(s, i);
}
fill_fail_output();
string text;
cin >> text;
search(text);
erase(root);
}
I am trying to code a c++ program for sorted insert of a linked list. I have given the code below. The problem is when doing my second insert i.e., insert(&head, 45); the head value is becoming 0 inside insert() function. I could not insert my second element and getting errors. Can anyone please help.
#include "stdafx.h"
#include <conio.h>
#include <iostream>
using namespace std;
struct node
{
int data;
node *next;
};
void insert (node** head, int key)
{
if(*head == NULL)
{
cout <<"List is empty, Inserting at first posistion"<<endl;
*head = new node;
(*head)->data = key;
(*head)->data = NULL;
}
else
{
struct node* temp;
temp = new node;
temp = *head;
if(key < temp->data)
{
cout<<"Key is smaller than first element. Inserting at first and moving"<<endl;
struct node* ctemp = new node;
ctemp->data = key;
ctemp->next = (*head);
//delete(ctemp);
return;
}
while(temp->next != NULL)
{
if(key > temp->data)
{
temp = temp->next;
}else
{
cout<<"Inserting the data at middle"<<temp->data<<" here"<<endl;
struct node* temp1 = new node;
temp1->data = key;
temp1->next = temp->next;
temp->next = temp1;
delete(temp1);
return;
}
}
if(key > temp->data)
{
cout<<"Inserting at last"<<endl;
struct node* last = new node;
last->data = key;
last->next = NULL;
temp->next = last;
delete(last);
return;
}
}
}
void print(struct node *head)
{
struct node* temp = head;
cout<<"Element in the list"<<endl;
while(temp != NULL)
{
cout<<temp->data<<"->";
temp = temp->next;
}
delete(temp);
}
int main()
{
struct node* head = NULL;
insert(&head, 21);
insert(&head, 45);
insert(&head, 5);
print(head);
getch();
delete(head);
return 0;
}
Change (*head)->data = NULL; to (*head)->next = NULL; if the list is empty.
I am using third party API which I get streams from a callback function
int OnNewImage(BYTE *pData, int nLen)
When I run a simple C++ sample program from console
int continue = 1;
int OnNewImage(BYTE *pData, int nLen)
{
std::cout << "On new image is called" << std::endl;
return continue;
}
int main()
{
// This will block
int result = DownloadStream(/*params*/...,OnNewImage /*callbackfunction*/);
return 0;
}
I get no memory leaks.[ memory does not increase ]
But When I use this callback function in a directshow filter, it
produce memory leaks.[ memory increase regularly]
What may cause this? And how can I fix it? Any ideas?
UPDATE: My DirectShow Filter structure
What I do:
Basically
I get streams at "unsigned __stdcall DVRStreamThread(LPVOID
pvParam)" function which call back OnNewImage
Then i insert frames into my queue inside that callback[OnNewImage]
Finally At FillBuffer I consume frames from queue.
It is am h264 stream. I can able to set simple graph like this
MySourceFilter ---> H264 Decoder ---> Video Renderer
Here is my FilterSourceCode:
Well I have a simple queue which i insert incoming frames then consume:
SynchronisedQueue
template <typename T>
class SynchronisedQueue
{
public:
void Enqueue(const T& data)
{
boost::unique_lock<boost::mutex> lock(queueMutex);
dataQueue.push(data);
conditionVariable.notify_one();
}
T Dequeue()
{
boost::unique_lock<boost::mutex> lock(queueMutex);
while (dataQueue.size()==0)
{
conditionVariable.wait(lock);
}
T result=dataQueue.front(); dataQueue.pop();
return result;
}
int Size()
{
boost::unique_lock<boost::mutex> lock(queueMutex);
int size = dataQueue.size();
return size;
}
private:
std::queue<T> dataQueue;
boost::mutex queueMutex;
boost::condition_variable conditionVariable;
};
Then My Filter:
DvrSourceFilter [ header]
#define DVRSourceFilterName L"DVRDirectShowFilter"
#include <streams.h>
#include <process.h>
#include <MyDvrApi.h>
#include "SynchronisedQueue.h"
// {F89A85DA-F77C-4d44-893B-CCA43A49E7EF}
DEFINE_GUID(CLSID_DVRSourceFilter,
0xf89a85da, 0xf77c, 0x4d44, 0x89, 0x3b, 0xcc, 0xa4, 0x3a, 0x49, 0xe7, 0xef);
class DECLSPEC_UUID("34363248-0000-0010-8000-00AA00389B71") Subtype_H264;
class DVRSourceFilter;
using namespace std;
/*
* **********************
* DVRPin
* **********************
*/
class DVRPin : public CSourceStream
{
public:
DVRPin(HRESULT *phr, DVRSourceFilter *pFilter);
~DVRPin();
// Override the version that offers exactly one media type
HRESULT GetMediaType(CMediaType *pMediaType);
HRESULT DecideBufferSize(IMemAllocator *pAlloc, ALLOCATOR_PROPERTIES *pRequest);
HRESULT FillBuffer(IMediaSample *pSample);
static int OnNewImage(void *pUser, BYTE *pData, int nLen, int nCh, int tMts, int nType, void *returnHandle);
// Setters
void SetDvrIp(char* dvrIp);
void SetDvrPort( int dvrPort);
void SetDvrUserName( char * userName);
void SetDvrPassword(char* password);
void SetStartTime(int startTime);
void SetMilliSecond(int milliSecond);
void SetChannelNumber(int channelNumber);
void SetSize(int width, int height);
// Getters
char* GetDvrIp();
int GetDvrPort();
char* GetDvrUserName();
char* GetDvrPassword();
int GetStartTime();
int GetMilliSecond();
int GetChannelNumber();
int GetMode();
public:
char* dvrIp;
int dvrPort;
char* userName;
char* password;
int startTime;
int milliSecond;
int channelNumber;
BITMAPINFOHEADER m_bmpInfo;
BYTE* m_RGB24Buffer;
DWORD m_RGB24BufferSize;
bool streamCompleted;
int hDecHandle;
HANDLE m_hDVRStreamThreadHandle;
unsigned int m_dwThreadID;
SynchronisedQueue<std::vector<BYTE>> IncomingFramesQueue;
protected:
virtual HRESULT OnThreadCreate();
virtual HRESULT OnThreadDestroy();
virtual HRESULT DoBufferProcessingLoop();
};
/*
* **********************
* DVRSourceFilter
* *********************
*
*/
class DVRSourceFilter : public CSource
{
public:
DECLARE_IUNKNOWN;
static CUnknown * WINAPI CreateInstance(IUnknown *pUnk, HRESULT *phr);
STDMETHODIMP NonDelegatingQueryInterface(REFIID riid, void **ppv);
void SetDVRLiveParameters(char* dvrIP, int dvrPort, char* userName, char* password, int channelNumber, int width, int height);
private:
DVRSourceFilter(IUnknown *pUnk, HRESULT *phr);
~DVRSourceFilter();
private:
DVRPin *m_pPin;
};
DvrSourceFilter [implementation]
#include "DvrSourceFilter.h"
unsigned __stdcall DVRStreamThread(LPVOID pvParam)
{
DVRPin* streamReader = (DVRPin*)pvParam;
int channelBits = 1 << (streamReader->channelNumber - 1);
streamReader->m_RGB24BufferSize = streamReader->m_bmpInfo.biWidth * streamReader->m_bmpInfo.biHeight * 3;
streamReader->m_RGB24Buffer = (BYTE*)malloc(streamReader->m_RGB24BufferSize);
DownloadStream((LPCTSTR)streamReader->dvrIp,
streamReader->dvrPort , (LPCTSTR)streamReader->userName ,
(LPCTSTR)streamReader->password , channelBits, channelBits,
streamReader->startTime, streamReader->milliSecond,
streamReader->OnNewImage, (void*)streamReader);
streamReader->startTime = -2; // End Of Stream
return 0;
}
/*
* ******************
* DVRPin Class
* ******************
*/
DVRPin::DVRPin(HRESULT *phr, DVRSourceFilter *pFilter)
: CSourceStream(NAME("DVR Source Bitmap"), phr, pFilter, L"Out")
{
m_bmpInfo.biSize = sizeof(BITMAPINFOHEADER);
m_bmpInfo.biCompression = BI_RGB;
m_bmpInfo.biBitCount = 24;
m_bmpInfo.biPlanes = 1;
m_bmpInfo.biClrImportant = 0;
m_bmpInfo.biClrUsed = 0;
m_bmpInfo.biXPelsPerMeter = 0;
m_bmpInfo.biYPelsPerMeter = 0;
hDecHandle = 0;
m_RGB24Buffer = NULL;
m_RGB24BufferSize = 0;
streamCompleted = false;
startTime = -1; // Live Stream
*phr = S_OK;
}
DVRPin::~DVRPin()
{
}
int DVRPin::OnNewImage(void *pUser, BYTE *pData, int nLen, int nCh, int tMts, int nType, void *returnHandle)
{
DVRPin* reader = (DVRPin*)pUser;
if(reader->streamCompleted)
{
return false;
}
if(pData)
{
std::vector<BYTE> vecFrame(pData, pData + nLen/sizeof(pData[0]));
reader->IncomingFramesQueue.Enqueue(vecFrame);
}
return !reader->streamCompleted;
}
HRESULT DVRPin::OnThreadCreate()
{
m_hDVRStreamThreadHandle =
(HANDLE)_beginthreadex(NULL, 0, &DVRStreamThread, (void*)this, 0, &m_dwThreadID);
return S_OK;
}
HRESULT DVRPin::OnThreadDestroy() {
streamCompleted = true;
_endthreadex(0);
CloseHandle(m_hDVRStreamThreadHandle);
return S_OK;
}
HRESULT DVRPin::GetMediaType(CMediaType *pMediaType)
{
CAutoLock cAutoLock(m_pFilter->pStateLock());
CheckPointer(pMediaType, E_POINTER);
VIDEOINFOHEADER* pvi = (VIDEOINFOHEADER*)pMediaType->AllocFormatBuffer(sizeof(VIDEOINFOHEADER));
if (pvi == 0)
return(E_OUTOFMEMORY);
ZeroMemory(pvi, pMediaType->cbFormat);
pvi->bmiHeader = m_bmpInfo;
pvi->bmiHeader.biSizeImage = GetBitmapSize(&pvi->bmiHeader);
SetRectEmpty(&(pvi->rcSource));
SetRectEmpty(&(pvi->rcTarget));
pMediaType->SetType(&MEDIATYPE_Video);
pMediaType->SetFormatType(&FORMAT_VideoInfo);
pMediaType->SetTemporalCompression(FALSE);
// Work out the GUID for the subtype from the header info.
const GUID SubTypeGUID = __uuidof(Subtype_H264);//GetBitmapSubtype(&pvi->bmiHeader);
pMediaType->SetSubtype(&SubTypeGUID);
pMediaType->SetSampleSize(pvi->bmiHeader.biSizeImage);
return S_OK;
}
HRESULT DVRPin::DecideBufferSize(IMemAllocator *pAlloc, ALLOCATOR_PROPERTIES *pRequest)
{
HRESULT hr;
CAutoLock cAutoLock(m_pFilter->pStateLock());
CheckPointer(pAlloc, E_POINTER);
CheckPointer(pRequest, E_POINTER);
VIDEOINFOHEADER *pvi = (VIDEOINFOHEADER*) m_mt.Format();
if (pRequest->cBuffers == 0)
{
pRequest->cBuffers = 2;
}
pRequest->cbBuffer = pvi->bmiHeader.biSizeImage;
ALLOCATOR_PROPERTIES Actual;
hr = pAlloc->SetProperties(pRequest, &Actual);
if (FAILED(hr))
{
return hr;
}
if (Actual.cbBuffer < pRequest->cbBuffer)
{
return E_FAIL;
}
return S_OK;
}
HRESULT DVRPin::FillBuffer(IMediaSample *pSample)
{
if(!streamCompleted)
{
CAutoLock cAutoLock(m_pLock);
HRESULT hr;
BYTE* pData = NULL;
hr = pSample->GetPointer(&pData);
if(FAILED(hr))
{
pSample->Release();
return hr;
}
if(IncomingFramesQueue.Size() <= 0) {
return S_OK;
}
vector<BYTE> data = IncomingFramesQueue.Dequeue();
int dataSize = (int)data.size();
if(dataSize <= 0 || dataSize > 1000000)
{
return S_OK;
}
memcpy(pData, &data[0], dataSize);
hr = pSample->SetActualDataLength(dataSize);
if(FAILED(hr))
{
pSample->Release();
return hr;
}
hr = pSample->SetSyncPoint(TRUE);
if(FAILED(hr))
{
pSample->Release();
return hr;
}
pSample->Release();
}
return S_OK;
}
HRESULT DVRPin::DoBufferProcessingLoop() {
Command com;
REFERENCE_TIME rtNow = 0L;
REFERENCE_TIME rtAdvise = 0L;
OnThreadStartPlay();
do {
while (!streamCompleted && !CheckRequest(&com)) {
IncomingFramesQueue.WaitUntilHaveElements();
IMediaSample *pSample;
HRESULT hr = GetDeliveryBuffer(&pSample,NULL,NULL,FALSE);
if (FAILED(hr)) {
continue; // go round again. Perhaps the error will go away
// or the allocator is decommited & we will be asked to
// exit soon.
}
hr = FillBuffer(pSample);
if (hr == S_OK) {
Deliver(pSample);
} else if (hr == S_FALSE) {
pSample->Release();
DeliverEndOfStream();
return S_FALSE;
} else {
// Log Error
}
pSample->Release();
}
if (com == CMD_RUN || com == CMD_PAUSE)
com = GetRequest(); // throw command away
else if (com != CMD_STOP)
{
// Log Error
}
} while (!streamCompleted && com != CMD_STOP);
return S_OK;
}
void DVRPin::SetDvrIp( char* dvrIp )
{
this->dvrIp = dvrIp;
}
void DVRPin::SetDvrPort( int dvrPort )
{
this->dvrPort = dvrPort;
}
void DVRPin::SetDvrUserName( char * userName )
{
this->userName = userName;
}
void DVRPin::SetDvrPassword( char* password )
{
this->password = password;
}
void DVRPin::SetStartTime( int startTime )
{
this->startTime = startTime;
}
void DVRPin::SetMilliSecond( int milliSecond )
{
this->milliSecond = milliSecond;
}
void DVRPin::SetSize(int width, int height) {
m_bmpInfo.biWidth = width;
m_bmpInfo.biHeight = height;
m_bmpInfo.biSizeImage = GetBitmapSize(&m_bmpInfo);
}
char* DVRPin::GetDvrIp()
{
return dvrIp;
}
int DVRPin::GetDvrPort()
{
return dvrPort;
}
char* DVRPin::GetDvrUserName()
{
return userName;
}
char* DVRPin::GetDvrPassword()
{
return password;
}
int DVRPin::GetStartTime()
{
return startTime;
}
int DVRPin::GetMilliSecond()
{
return milliSecond;
}
void DVRPin::SetChannelNumber( int channelNumber )
{
this->channelNumber = channelNumber;
}
int DVRPin::GetChannelNumber()
{
return channelNumber;
}
/*
* ****************************
* DVRSourceFilter Class
* ***************************
*/
DVRSourceFilter::DVRSourceFilter(IUnknown *pUnk, HRESULT *phr)
: CSource(NAME("DVRSourceBitmap"), pUnk, CLSID_DVRSourceFilter)
{
// The pin magically adds itself to our pin array.
m_pPin = new DVRPin(phr, this);
// Just for test at graph studio
SetDVRLiveParameters("192.168.3.151", 7000, "admin", "000000", 3, 352, 288);
if (phr)
{
if (m_pPin == NULL)
*phr = E_OUTOFMEMORY;
else
*phr = S_OK;
}
}
DVRSourceFilter::~DVRSourceFilter()
{
delete m_pPin;
}
CUnknown * WINAPI DVRSourceFilter::CreateInstance(IUnknown *pUnk, HRESULT *phr)
{
DVRSourceFilter *pNewFilter = new DVRSourceFilter(pUnk, phr);
if (phr)
{
if (pNewFilter == NULL)
*phr = E_OUTOFMEMORY;
else
*phr = S_OK;
}
return pNewFilter;
}
STDMETHODIMP DVRSourceFilter::NonDelegatingQueryInterface( REFIID riid, void **ppv )
{
return CSource::NonDelegatingQueryInterface(riid, ppv);
}
void DVRSourceFilter::SetDVRLiveParameters( char* dvrIP, int dvrPort, char* userName, char* password, int channelNumber, int width, int height )
{
m_pPin->SetDvrIp(dvrIP);
m_pPin->SetDvrPort(dvrPort);
m_pPin->SetDvrUserName(userName);
m_pPin->SetDvrPassword(password);
m_pPin->SetChannelNumber(channelNumber);
m_pPin->SetStartTime(-1);// Live Stream
m_pPin->SetMilliSecond(0);
m_pPin->SetSize(width, height);
}
...
To make directshow Filter simple [ to understand memory leak source], just implement OnNewImage function and FillBufferFunction as "dummy", but still has memory leak:
int DVRPin::OnNewImage(void *pUser, BYTE *pData, int nLen, int nCh, int tMts, int nType, void *returnHandle)
{
return 1; // for not to end call back
}
HRESULT DVRPin::FillBuffer(IMediaSample *pSample)
{
pSample->Release();
return S_OK;
}
In DVRStreamThread, you have:
streamReader->m_RGB24Buffer = (BYTE*)malloc(streamReader->m_RGB24BufferSize);
But I don't see a matching call to free() anywhere. When your DVRPin object is deleted, you will have to explicitly free the data pointed to by its m_RGB24Buffer member.
First thing I see, is that your destructors are not virtual. This might be a cause of leaks when release is not taking place when inheritance is used. See related article about the necessity of virtual destructors.
Modified the below circular queue code for my app.
This queue can hold 32 elements max and I have declared the elements as a structure array inside the class. For adding an element to the queue you have to call CreateElement() functions, which checks for a free element and returns an index. When I reuse an element after processing the following line in the CreateElement functions crashes
boost::shared_array<char> tData(new char[bufferSize]);
m_QueueStructure[queueElems].data = tData;
As per documentation, the assignment operator is supposed to destroy the earlier object and assign the new one. Why is it crashing? Can someone tell me where am I screwing?
#include "boost/thread/condition.hpp"
#include "boost/smart_ptr/shared_array.hpp"
#include <queue>
#define MAX_QUEUE_ELEMENTS 32
typedef struct queue_elem
{
bool inUse;
int index;
int packetType;
unsigned long compressedLength;
unsigned long uncompressedLength;
boost::shared_array<char> data;
}Data;
class CQueue
{
private:
int m_CurrentElementsOfQueue;
std::queue<Data> the_queue;
mutable boost::mutex the_mutex;
boost::condition_variable the_condition_variable;
Data m_QueueStructure[MAX_QUEUE_ELEMENTS];
public:
CQueue()
{
m_CurrentElementsOfQueue = 0;
for(int i = 0; i < MAX_QUEUE_ELEMENTS; i++)
{
m_QueueStructure[i].inUse = false;
m_QueueStructure[i].index = i;
}
}
~CQueue()
{
for(int i = 0; i < m_CurrentElementsOfQueue; i++)
{
int index = wait_and_pop();
Data& popped_value = m_QueueStructure[index];
popped_value.inUse = false;
}
m_CurrentElementsOfQueue = 0;
}
void push(Data const& data)
{
boost::mutex::scoped_lock lock(the_mutex);
the_queue.push(data);
lock.unlock();
the_condition_variable.notify_one();
}
bool empty() const
{
boost::mutex::scoped_lock lock(the_mutex);
return the_queue.empty();
}
bool try_pop(Data& popped_value)
{
boost::mutex::scoped_lock lock(the_mutex);
if(the_queue.empty())
{
return false;
}
popped_value=the_queue.front();
the_queue.pop();
return true;
}
int wait_and_pop()
{
boost::mutex::scoped_lock lock(the_mutex);
while(the_queue.empty())
{
the_condition_variable.wait(lock);
}
Data& popped_value=the_queue.front();
the_queue.pop();
return popped_value.index;
}
int CreateElement(int bufferSize, unsigned long _compressedLength,
unsigned long _uncompressedLength, int _packetType) /* Send data length for this function */
{
int queueElems = 0;
if(m_CurrentElementsOfQueue == 32)
{
CCommonException ex(QERROR, QUEUE_FULL, "Circular Buffer Queue is full");
throw ex;
}
for(queueElems = 0; queueElems < MAX_QUEUE_ELEMENTS; queueElems++)
{
if(m_QueueStructure[queueElems].inUse == false)
break;
}
boost::shared_array<char> tData(new char[bufferSize]);
m_QueueStructure[queueElems].data = tData;
m_QueueStructure[queueElems].inUse = true;
m_QueueStructure[queueElems].compressedLength = _compressedLength;
m_QueueStructure[queueElems].uncompressedLength = _uncompressedLength;
m_QueueStructure[queueElems].packetType = _packetType;
m_CurrentElementsOfQueue++;
return queueElems;
}
Data& GetElement(int index)
{
Data& DataElement = m_QueueStructure[index];
return DataElement;
}
void ClearElementIndex(Data& delValue)
{
m_CurrentElementsOfQueue--;
delValue.inUse = false;
}
};
for(queueElems = 0; queueElems < MAX_QUEUE_ELEMENTS; queueElems++) after looping queueElems has value 32 but in your m_QueueStructure only 32 elements so you trying to access m_QueueStructure[queueElems].data to 33rd element. That the problem.
EDIT: try use m_QueueStructure[queueElems].data.reset(new char[bufferSize]);
Solved the problem. Two changes I did. In the wait_and_pop function, I was returning an index rather than a Data&. When I returned Data&, that solved the assignment problem. Another crash was happening due to a memset of a shared_array.get(). Lesson learnt, never memset a shared_array or a shared_ptr.