diff options
Diffstat (limited to 'plugins/FreeImage/Source/FreeImage/CacheFile.cpp')
| -rw-r--r-- | plugins/FreeImage/Source/FreeImage/CacheFile.cpp | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/plugins/FreeImage/Source/FreeImage/CacheFile.cpp b/plugins/FreeImage/Source/FreeImage/CacheFile.cpp new file mode 100644 index 0000000000..fc1ba0d798 --- /dev/null +++ b/plugins/FreeImage/Source/FreeImage/CacheFile.cpp @@ -0,0 +1,271 @@ +// ==========================================================
+// Multi-Page functions
+//
+// Design and implementation by
+// - Floris van den Berg (flvdberg@wxs.nl)
+// - checkered (checkered@users.sourceforge.net)
+//
+// This file is part of FreeImage 3
+//
+// COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY
+// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES
+// THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE
+// OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED
+// CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT
+// THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY
+// SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL
+// PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER
+// THIS DISCLAIMER.
+//
+// Use at your own risk!
+// ==========================================================
+
+#ifdef _MSC_VER
+#pragma warning (disable : 4786) // identifier was truncated to 'number' characters
+#endif
+
+#include "CacheFile.h"
+
+// ----------------------------------------------------------
+
+CacheFile::CacheFile(const std::string filename, BOOL keep_in_memory) :
+m_file(NULL),
+m_filename(filename),
+m_free_pages(),
+m_page_cache_mem(),
+m_page_cache_disk(),
+m_page_map(),
+m_page_count(0),
+m_current_block(NULL),
+m_keep_in_memory(keep_in_memory) {
+}
+
+CacheFile::~CacheFile() {
+}
+
+BOOL
+CacheFile::open() {
+ if ((!m_filename.empty()) && (!m_keep_in_memory)) {
+ m_file = fopen(m_filename.c_str(), "w+b");
+ return (m_file != NULL);
+ }
+
+ return (m_keep_in_memory == TRUE);
+}
+
+void
+CacheFile::close() {
+ // dispose the cache entries
+
+ while (!m_page_cache_disk.empty()) {
+ Block *block = *m_page_cache_disk.begin();
+ m_page_cache_disk.pop_front();
+ delete [] block->data;
+ delete block;
+ }
+ while (!m_page_cache_mem.empty()) {
+ Block *block = *m_page_cache_mem.begin();
+ m_page_cache_mem.pop_front();
+ delete [] block->data;
+ delete block;
+ }
+
+ if (m_file) {
+ // close the file
+
+ fclose(m_file);
+
+ // delete the file
+
+ remove(m_filename.c_str());
+ }
+}
+
+void
+CacheFile::cleanupMemCache() {
+ if (!m_keep_in_memory) {
+ if (m_page_cache_mem.size() > CACHE_SIZE) {
+ // flush the least used block to file
+
+ Block *old_block = m_page_cache_mem.back();
+ fseek(m_file, old_block->nr * BLOCK_SIZE, SEEK_SET);
+ fwrite(old_block->data, BLOCK_SIZE, 1, m_file);
+
+ // remove the data
+
+ delete [] old_block->data;
+ old_block->data = NULL;
+
+ // move the block to another list
+
+ m_page_cache_disk.splice(m_page_cache_disk.begin(), m_page_cache_mem, --m_page_cache_mem.end());
+ m_page_map[old_block->nr] = m_page_cache_disk.begin();
+ }
+ }
+}
+
+int
+CacheFile::allocateBlock() {
+ Block *block = new Block;
+ block->data = new BYTE[BLOCK_SIZE];
+ block->next = 0;
+
+ if (!m_free_pages.empty()) {
+ block->nr = *m_free_pages.begin();
+ m_free_pages.pop_front();
+ } else {
+ block->nr = m_page_count++;
+ }
+
+ m_page_cache_mem.push_front(block);
+ m_page_map[block->nr] = m_page_cache_mem.begin();
+
+ cleanupMemCache();
+
+ return block->nr;
+}
+
+Block *
+CacheFile::lockBlock(int nr) {
+ if (m_current_block == NULL) {
+ PageMapIt it = m_page_map.find(nr);
+
+ if (it != m_page_map.end()) {
+ m_current_block = *(it->second);
+
+ // the block is swapped out to disc. load it back
+ // and remove the block from the cache. it might get cached
+ // again as soon as the memory buffer fills up
+
+ if (m_current_block->data == NULL) {
+ m_current_block->data = new BYTE[BLOCK_SIZE];
+
+ fseek(m_file, m_current_block->nr * BLOCK_SIZE, SEEK_SET);
+ fread(m_current_block->data, BLOCK_SIZE, 1, m_file);
+
+ m_page_cache_mem.splice(m_page_cache_mem.begin(), m_page_cache_disk, it->second);
+ m_page_map[nr] = m_page_cache_mem.begin();
+ }
+
+ // if the memory cache size is too large, swap an item to disc
+
+ cleanupMemCache();
+
+ // return the current block
+
+ return m_current_block;
+ }
+ }
+
+ return NULL;
+}
+
+BOOL
+CacheFile::unlockBlock(int nr) {
+ if (m_current_block) {
+ m_current_block = NULL;
+
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+BOOL
+CacheFile::deleteBlock(int nr) {
+ if (!m_current_block) {
+ PageMapIt it = m_page_map.find(nr);
+
+ // remove block from cache
+
+ if (it != m_page_map.end())
+ m_page_map.erase(nr);
+
+ // add block to free page list
+
+ m_free_pages.push_back(nr);
+
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+BOOL
+CacheFile::readFile(BYTE *data, int nr, int size) {
+ if ((data) && (size > 0)) {
+ int s = 0;
+ int block_nr = nr;
+
+ do {
+ int copy_nr = block_nr;
+
+ Block *block = lockBlock(copy_nr);
+
+ block_nr = block->next;
+
+ memcpy(data + s, block->data, (s + BLOCK_SIZE > size) ? size - s : BLOCK_SIZE);
+
+ unlockBlock(copy_nr);
+
+ s += BLOCK_SIZE;
+ } while (block_nr != 0);
+
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+int
+CacheFile::writeFile(BYTE *data, int size) {
+ if ((data) && (size > 0)) {
+ int nr_blocks_required = 1 + (size / BLOCK_SIZE);
+ int count = 0;
+ int s = 0;
+ int stored_alloc;
+ int alloc;
+
+ stored_alloc = alloc = allocateBlock();
+
+ do {
+ int copy_alloc = alloc;
+
+ Block *block = lockBlock(copy_alloc);
+
+ block->next = 0;
+
+ memcpy(block->data, data + s, (s + BLOCK_SIZE > size) ? size - s : BLOCK_SIZE);
+
+ if (count + 1 < nr_blocks_required)
+ alloc = block->next = allocateBlock();
+
+ unlockBlock(copy_alloc);
+
+ s += BLOCK_SIZE;
+ } while (++count < nr_blocks_required);
+
+ return stored_alloc;
+ }
+
+ return 0;
+}
+
+void
+CacheFile::deleteFile(int nr) {
+ do {
+ Block *block = lockBlock(nr);
+
+ if (block == NULL)
+ break;
+
+ int next = block->next;
+
+ unlockBlock(nr);
+
+ deleteBlock(nr);
+
+ nr = next;
+ } while (nr != 0);
+}
+
|