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Asynchronous streaming and memory management improvements in progress.

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--HG--
branch : async_streaming
This commit is contained in:
Kearwood Gilbert
2013-11-01 23:17:04 -07:00
parent 63503393a4
commit ab808fc3e1
13 changed files with 133 additions and 47 deletions
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30
KREngine/kraken/KRDataBlock.cpp
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@@ -37,6 +37,7 @@ KRDataBlock::KRDataBlock() {
m_data_size = 0;
m_data_offset = 0;
m_fdPackFile = 0;
m_fileName = "";
m_mmapData = NULL;
m_fileOwnerDataBlock = NULL;
m_bMalloced = false;
@@ -68,6 +69,7 @@ void KRDataBlock::unload()
m_data_size = 0;
m_data_offset = 0;
m_fdPackFile = 0;
m_fileName = "";
m_mmapData = NULL;
m_fileOwnerDataBlock = NULL;
m_bReadOnly = false;
@@ -95,6 +97,7 @@ bool KRDataBlock::load(const std::string &path)
m_fdPackFile = open(path.c_str(), O_RDONLY);
if(m_fdPackFile >= 0) {
m_fileOwnerDataBlock = this;
m_fileName = path;
if(fstat(m_fdPackFile, &statbuf) >= 0) {
m_data_size = statbuf.st_size;
m_data_offset = 0;
@@ -117,9 +120,9 @@ KRDataBlock *KRDataBlock::getSubBlock(int start, int length)
if(m_fdPackFile) {
new_block->m_fdPackFile = m_fdPackFile;
new_block->m_fileOwnerDataBlock = m_fileOwnerDataBlock;
new_block->m_data_offset = start;
new_block->m_data_offset = start + m_data_offset;
} else if(m_bMalloced) {
new_block->m_data = (unsigned char *)m_data + start;
new_block->m_data = (unsigned char *)m_data + start + m_data_offset;
}
new_block->m_bReadOnly = true;
return new_block;
@@ -189,16 +192,20 @@ void KRDataBlock::append(void *data, size_t size) {
// Copy the entire data block to the destination pointer
void KRDataBlock::copy(void *dest) {
lock();
memcpy((unsigned char *)dest, m_data, m_data_size);
unlock();
copy(dest, 0, m_data_size);
}
// Copy a range of data to the destination pointer
void KRDataBlock::copy(void *dest, int start, int count) {
lock();
memcpy((unsigned char *)dest, (unsigned char *)m_data + start, count);
unlock();
if(m_lockCount == 0 && m_fdPackFile != 0) {
// Optimization: If we haven't mmap'ed or malloced the data already, pread() it directly from the file into the buffer
ssize_t r = pread(m_fdPackFile, dest, count, start + m_data_offset);
assert(r != -1);
} else {
lock();
memcpy((unsigned char *)dest, (unsigned char *)m_data + start, count);
unlock();
}
}
// Append data to the end of the block, increasing the size of the block and making it read-write.
@@ -249,25 +256,26 @@ bool KRDataBlock::save(const std::string& path) {
// Get contents as a string
std::string KRDataBlock::getString()
{
lock();
KRDataBlock b;
b.append(*this);
b.append((void *)"\0", 1); // Ensure data is null terminated, to read as a string safely
b.lock();
std::string ret = std::string((char *)b.getStart());
b.unlock();
unlock();
return ret;
}
// Lock the memory, forcing it to be loaded into a contiguous block of address space
void KRDataBlock::lock()
{
m_lockCount++;
if(m_lockCount == 1) {
// Memory mapped file; ensure data is mapped to ram
if(m_fdPackFile) {
fprintf(stderr, "KRDataBlock::lock - \"%s\" (%i)\n", m_fileOwnerDataBlock->m_fileName.c_str(), m_lockCount);
// Round m_data_offset down to the next memory page, as required by mmap
size_t alignment_offset = m_data_offset & (KRAKEN_MEM_PAGE_SIZE - 1);
if ((m_mmapData = mmap(0, m_data_size + alignment_offset, m_bReadOnly ? PROT_READ : PROT_WRITE, MAP_SHARED, m_fdPackFile, m_data_offset - alignment_offset)) == (caddr_t) -1) {
@@ -290,6 +298,8 @@ void KRDataBlock::unlock()
// Memory mapped file; ensure data is unmapped from ram
if(m_fdPackFile) {
fprintf(stderr, "KRDataBlock::unlock - \"%s\" (%i)\n", m_fileOwnerDataBlock->m_fileName.c_str(), m_lockCount);
munmap(m_mmapData, m_data_size);
m_data = NULL;
m_mmapData = NULL;