VVVVVV mmaped music.

mmap-patch.diff

diff --git a/desktop_version/CMakeLists.txt b/desktop_version/CMakeLists.txt
index 9e60db8b..4d522961 100644
--- a/desktop_version/CMakeLists.txt
+++ b/desktop_version/CMakeLists.txt
@@ -22,7 +22,7 @@ if(OFFICIAL_BUILD AND NOT MAKEANDPLAY)
 endif()
 
 option(REMOVE_ABSOLUTE_PATHS "If supported by the compiler, replace all absolute paths to source directories compiled into the binary (if any) with relative paths" ON)
-
+option(USE_MMAP "Use memory mapped blobs where possible, lowering physical memory requirements." OFF)
 
 # Architecture Flags
 if(APPLE)
@@ -396,6 +396,10 @@ if(REMOVE_ABSOLUTE_PATHS)
     endif()
 endif()
 
+if(USE_MMAP)
+    message(STATUS "Using memory mapped blobs")
+    target_compile_definitions(VVVVVV PRIVATE -DUSE_MMAP=1)
+endif()
 
 target_compile_options(VVVVVV PRIVATE ${GLOBAL_COMPILE_FLAGS})
 
diff --git a/desktop_version/src/BinaryBlob.cpp b/desktop_version/src/BinaryBlob.cpp
index 62d99f19..996328a3 100644
--- a/desktop_version/src/BinaryBlob.cpp
+++ b/desktop_version/src/BinaryBlob.cpp
@@ -18,6 +18,10 @@ binaryBlob::binaryBlob(void)
 #endif
     SDL_zeroa(m_headers);
     SDL_zeroa(m_memblocks);
+#ifdef USE_MMAP
+    m_mmap = MAP_FAILED;
+    m_fd = -1;
+#endif
 }
 
 #ifdef VVV_COMPILEMUSIC
@@ -83,20 +87,41 @@ void binaryBlob::writeBinaryBlob(const char* _name)
 
 bool binaryBlob::unPackBinary(const char* name)
 {
-    return FILESYSTEM_loadBinaryBlob(this, name);
+    if (FILESYSTEM_mapBinaryBlob(this, name))
+        return true;
+    if (FILESYSTEM_loadBinaryBlob(this, name))
+        return true;
+
+    vlog_error("%s: Failed to read blob", name);
+    return false;
 }
 
 void binaryBlob::clear(void)
 {
-    for (size_t i = 0; i < SDL_arraysize(m_headers); i += 1)
+#ifdef USE_MMAP
+    if (m_fd >= 0)
     {
-        if (m_memblocks[i] != NULL)
+        munmap(m_mmap, m_mapsz);
+        close(m_fd);
+        m_mmap = MAP_FAILED;
+        m_mapsz = 0;
+        m_fd = -1;
+        SDL_zeroa(m_memblocks);
+        SDL_zeroa(m_headers);
+    }
+    else
+#endif //USE_MMAP
+    {
+        for (size_t i = 0; i < SDL_arraysize(m_headers); i += 1)
         {
-            VVV_free(m_memblocks[i]);
+            if (m_memblocks[i] != NULL)
+            {
+                VVV_free(m_memblocks[i]);
+            }
         }
+        SDL_zeroa(m_memblocks);
+        SDL_zeroa(m_headers);
     }
-    SDL_zeroa(m_memblocks);
-    SDL_zeroa(m_headers);
 }
 
 int binaryBlob::getIndex(const char* _name)
diff --git a/desktop_version/src/BinaryBlob.h b/desktop_version/src/BinaryBlob.h
index f8089930..ea4c95d2 100644
--- a/desktop_version/src/BinaryBlob.h
+++ b/desktop_version/src/BinaryBlob.h
@@ -1,6 +1,13 @@
 #ifndef BINARYBLOB_H
 #define BINARYBLOB_H
 
+#ifdef USE_MMAP
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <unistd.h>
+#endif //USE_MMAP
 #include <stddef.h>
 #include <stdint.h>
 
@@ -63,6 +70,11 @@ public:
 #endif
     resourceheader m_headers[max_headers];
     char* m_memblocks[max_headers];
+#ifdef USE_MMAP
+    void *m_mmap;
+    long long unsigned m_mapsz;
+    int m_fd;
+#endif //USE_MMAP
 };
 
 
diff --git a/desktop_version/src/FileSystemUtils.cpp b/desktop_version/src/FileSystemUtils.cpp
index 5643182d..83fe6047 100644
--- a/desktop_version/src/FileSystemUtils.cpp
+++ b/desktop_version/src/FileSystemUtils.cpp
@@ -1071,6 +1071,88 @@ fail:
     return true;
 }
 
+#ifdef USE_MMAP
+bool FILESYSTEM_mapBinaryBlob(binaryBlob *blob, const char *filename)
+{
+    int valid = 0;
+    uintptr_t offset = 0;
+    const char *fs_realdir;
+    char fs_path[MAX_PATH];
+    struct stat s_stat;
+
+    fs_realdir = PHYSFS_getRealDir(filename);
+    if (fs_realdir == NULL)
+    {
+        vlog_warn("%s: Unable to find file", filename);
+        return false;
+    }
+    snprintf(fs_path, sizeof(fs_path)-1, "%s%s%s", fs_realdir, pathSep, filename);
+
+    blob->m_fd = open(fs_path, O_RDONLY);
+    if (blob->m_fd < 0)
+    {
+        vlog_warn("%s: Unable to open file", fs_path);
+        return false;
+    }
+
+    fstat(blob->m_fd, &s_stat);
+    blob->m_mapsz = s_stat.st_size;
+
+    blob->m_mmap = mmap(NULL, blob->m_mapsz, PROT_READ, MAP_PRIVATE, blob->m_fd, 0);
+    if (blob->m_mmap == MAP_FAILED)
+    {
+        vlog_error("%s: Unable to mmap file", fs_path);
+        goto clean_mmap;
+    }
+
+    offset = sizeof(blob->m_headers);
+
+    SDL_memcpy(&blob->m_headers, blob->m_mmap, sizeof(blob->m_headers));
+    for (size_t i = 0; i < SDL_arraysize(blob->m_headers); i++)
+    {
+        resourceheader *header = &blob->m_headers[i];
+        char **memblock = &blob->m_memblocks[i];
+
+        header->name[sizeof(header->name) - 1] = '\0';
+        if (header->size < 1) {
+            vlog_error("%s: Header %li's size value is zero or negative", fs_path, i);
+            goto fail_mmaped_header;
+        }
+
+        *memblock = (char*)((uintptr_t)blob->m_mmap + offset);
+        offset += header->size;
+        valid += 1;
+        continue;
+fail_mmaped_header:
+        header->valid = false;
+    }
+
+    if (valid == 0)
+    {
+        goto clean_mmap;
+    }
+
+    return true;
+clean_mmap:
+    if (blob->m_fd > 0) {
+        close(blob->m_fd);
+        blob->m_fd = -1;
+    }
+    if (blob->m_mmap != MAP_FAILED) {
+        munmap(blob->m_mmap, blob->m_mapsz);
+        blob->m_mmap = MAP_FAILED;
+    }
+
+    return false;
+}
+#else //USE_MMAP
+bool FILESYSTEM_mapBinaryBlob(binaryBlob *blob, const char *filename)
+{
+    /* Implementation only available on POSIX. */
+    return false;
+}
+#endif
+
 bool FILESYSTEM_saveTiXml2Document(const char *name, tinyxml2::XMLDocument& doc, bool sync /*= true*/)
 {
     if (!isInit)
diff --git a/desktop_version/src/FileSystemUtils.h b/desktop_version/src/FileSystemUtils.h
index e5c65031..4281fd64 100644
--- a/desktop_version/src/FileSystemUtils.h
+++ b/desktop_version/src/FileSystemUtils.h
@@ -42,7 +42,7 @@ void FILESYSTEM_loadAssetToMemory(
 );
 
 bool FILESYSTEM_loadBinaryBlob(binaryBlob* blob, const char* filename);
-
+bool FILESYSTEM_mapBinaryBlob(binaryBlob *blob, const char *filename);
 bool FILESYSTEM_saveTiXml2Document(const char *name, tinyxml2::XMLDocument& doc, bool sync = true);
 bool FILESYSTEM_loadTiXml2Document(const char *name, tinyxml2::XMLDocument& doc);
 bool FILESYSTEM_loadAssetTiXml2Document(const char *name, tinyxml2::XMLDocument& doc);