Work in progress PAK extractor/insterter.

Makefile

@@ -41,7 +41,7 @@ ifeq ($(track), no)
     CFLAGS += -DNOTRACK
 endif
 
-OBJ_D = util.o code.o ast.o ir.o conout.o ftepp.o opts.o file.o utf8.o correct.o
+OBJ_D = util.o code.o ast.o ir.o conout.o ftepp.o opts.o file.o utf8.o correct.o pak.o
 OBJ_T = test.o util.o conout.o file.o
 OBJ_C = main.o lexer.o parser.o file.o
 OBJ_X = exec-standalone.o util.o conout.o file.o
@@ -202,6 +202,7 @@ opts.o: gmqcc.h opts.def
 file.o: gmqcc.h opts.def
 utf8.o: gmqcc.h opts.def
 correct.o: gmqcc.h opts.def
+pak.o: gmqcc.h opts.def
 
 test.o: gmqcc.h opts.def
 util.o: gmqcc.h opts.def

pak.c

@@ -0,0 +1,411 @@
+/*
+ * Copyright (C) 2013
+ *     Dale Weiler 
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <sys/stat.h>
+#include <dirent.h>
+#include "gmqcc.h"  
+
+typedef struct {
+    uint32_t magic;  /* "PACK" */
+
+    /*
+     * Offset to first directory entry in PAK file.  It's often
+     * best to store the directories at the end of the file opposed
+     * to the front, since it allows easy insertion without having
+     * to load the entire file into memory again.
+     */     
+    uint32_t diroff;
+    uint32_t dirlen;
+} pak_header_t;
+
+/*
+ * A directory, is sort of a "file entry".  The concept of
+ * a directory in Quake world is a "file entry/record". This
+ * describes a file (with directories/nested ones too in it's
+ * file name).  Hence it can be a file, file with directory, or
+ * file with directories.
+ */ 
+typedef struct {
+    char     name[56];
+    uint32_t pos;
+    uint32_t len;
+} pak_directory_t;
+
+/*
+ * Used to get the next token from a string, where the
+ * strings themselfs are seperated by chracters from
+ * `sep`.  This is essentially strsep.
+ */   
+static char *pak_tree_sep(char **str, const char *sep) {
+    char *beg = *str;
+    char *end;
+
+    if (!beg)
+        return NULL;
+
+    if (*(end = beg + strcspn(beg, sep)))
+        * end++ = '\0'; /* null terminate */
+    else
+          end   = 0;
+
+    *str = end;
+    return beg;
+}
+
+/*
+ * Used to spawn a directory when creating the pak directory structure/
+ * tree.  Think of this as mkdir(path, 0700).  We just cargo cult our
+ * own because _mkdir on windows is "illegal" for Windows8 Certification
+ * do to the requirement of SECURITY_ATTRIBUTES on everything.
+ */    
+static bool pak_tree_spawn(const char *path) {
+#ifdef _MSC_VER
+    return CreateDirectoryA(path, NULL); /* non-zero on success */
+#else
+    return !!(mkdir(path, 0700));        /* zero on success     */
+#endif
+}
+
+/*
+ * When given a string like "a/b/c/d/e/file"
+ * this function will handle the creation of
+ * the directory structure, included nested
+ * directories.
+ */    
+static void pak_tree_build(const char *entry) {
+    char *directory;
+    char *elements[28];
+    char *pathsplit;
+
+    size_t itr;
+    size_t jtr;
+
+    pathsplit = mem_a(56);
+    directory = mem_a(56);
+
+    strncpy(directory, entry, 56);
+    for (itr = 0; (elements[itr] = pak_tree_sep(&directory, "/")); itr++);
+    for (jtr = 0; jtr < itr - 1; jtr++) {
+        strcat(pathsplit, elements[jtr]);
+        strcat(pathsplit, "/");
+
+        pak_tree_spawn(pathsplit);
+    }
+
+    mem_d(pathsplit);
+    mem_d(directory);
+}
+
+typedef struct {
+    pak_directory_t *directories;
+    pak_header_t     header;
+    FILE            *handle;
+    bool             insert;
+} pak_file_t;
+
+pak_file_t *pak_open_read(const char *file) {
+    pak_file_t *pak;
+    size_t      itr;
+
+    if (!(pak = mem_a(sizeof(pak_file_t))))
+        return NULL;
+
+    if (!(pak->handle = file_open(file, "rb"))) {
+        mem_d(pak);
+        return NULL;
+    }
+
+    pak->directories = NULL;
+    pak->insert      = false; /* read doesn't allow insert */
+
+    memset         (&(pak->header), 0, sizeof(pak_header_t));
+    file_read      (&(pak->header), 1, sizeof(pak_header_t), pak->handle);
+    util_endianswap(&(pak->header), 1, sizeof(pak_header_t));
+
+    /*
+     * Every PAK file has "PACK" stored as little endian data in the
+     * header.  If this data cannot compare (as checked here), it's
+     * probably not a PAK file.
+     */    
+    if (!(memcmp(&(pak->header.magic), (const void*)"PACK", sizeof(uint32_t)))) {
+        file_close(pak->handle);
+        mem_d     (pak);
+        return NULL;
+    }
+
+    /*
+     * Time to read in the directory handles and prepare the directories
+     * vector.  We're going to be reading some the file inwards soon.
+     */      
+    file_seek(pak->handle, pak->header.diroff, SEEK_SET);
+
+    /*
+     * Read in all directories from the PAK file. These are considered
+     * to be the "file entries".
+     */   
+    for (itr = 0; itr < pak->header.dirlen / 64; itr++) {
+        pak_directory_t dir;
+        file_read      (&dir, 1, sizeof(pak_directory_t), pak->handle);
+        util_endianswap(&dir, 1, sizeof(pak_directory_t));
+
+        vec_push(pak->directories, dir);
+    }
+    return pak;
+}
+
+pak_file_t *pak_open_write(const char *file) {
+    pak_file_t *pak;
+
+    if (!(pak = mem_a(sizeof(pak_file_t))))
+        return NULL;
+
+    /*
+     * Generate the required directory structure / tree for
+     * writing this PAK file too.
+     */   
+    pak_tree_build(file);
+
+    if (!(pak->handle = file_open(file, "wb"))) {
+        /*
+         * The directory tree that was created, needs to be
+         * removed entierly if we failed to open a file.
+         */   
+        /* TODO backup directory clean */
+
+        return NULL;
+    }
+
+    memset(&(pak->header), 0, sizeof(pak_header_t));
+
+    /*
+     * We're in "insert" mode, we need to do things like header
+     * "patching" and writing the directories at the end of the
+     * file.
+     */
+    pak->insert = true;
+
+    /*
+     * A valid PAK file contains the magic "PACK" in it's header
+     * stored in little endian format.
+     */
+    memcpy(&(pak->header.magic), (const void*)"PACK", sizeof(uint32_t));
+
+    /*
+     * We need to write out the header since files will be wrote out to
+     * this even with directory entries, and that not wrote.  The header
+     * will need to be patched in later with a file_seek, and overwrite,
+     * we could use offsets and other trickery.  This is just easier.
+     */
+    file_write(&(pak->header), sizeof(pak_header_t), 1, pak->handle);
+
+    return pak;
+}
+
+bool pak_exists(pak_file_t *pak, const char *file, pak_directory_t **dir) {
+    size_t itr;
+
+    if (!pak || !file)
+        return false;
+
+    /*
+     * We could technically use a hashtable here.  But I don't think
+     * the lookup complexity is a performance concern.  This may be
+     * O(n) lookup.  But meh?
+     */    
+    for (itr = 0; itr < vec_size(pak->directories); itr++) {
+        if (!strcmp(pak->directories[itr].name, file)) {
+            /*
+             * Store back a pointer to the directory that matches
+             * the request if requested (NULL is not allowed).
+             */   
+            if (dir) {
+                *dir = &(pak->directories[itr]);
+            }
+            return true;
+        }
+    }
+
+    return false;
+}
+
+/*
+ * Extraction abilities.  These work as you expect them to.
+ */ 
+bool pak_extract_one(pak_file_t *pak, const char *file) {
+    pak_directory_t *dir = NULL;
+    unsigned char   *dat = NULL;
+    FILE            *out;
+
+    if (!pak_exists(pak, file, &dir)) {
+        return false;
+    }
+
+    if (!(dat = (unsigned char *)mem_a(dir->len))) {
+        return false;
+    }
+
+    /*
+     * Generate the directory structure / tree that will be required
+     * to store the extracted file.
+     */   
+    pak_tree_build(file);
+
+    /*
+     * Now create the file, if this operation fails.  Then abort
+     * It shouldn't fail though.
+     */   
+    if (!(out = file_open(file, "wb"))) {
+        mem_d(dat);
+        return false;
+    }
+
+
+    /* read */
+    file_seek (pak->handle, dir->pos, SEEK_SET);
+    file_read (dat, 1, dir->len, pak->handle);
+
+    /* write */
+    file_write(dat, 1, dir->len, out);
+
+    /* close */
+    file_close(out);
+
+    /* free */
+    mem_d(dat);
+
+    return true;
+}
+
+bool pak_extract_all(pak_file_t *pak) {
+    size_t itr;
+    for (itr = 0; itr < vec_size(pak->directories); itr++) {
+        if (!pak_extract_one(pak, pak->directories[itr].name))
+            return false;
+    }
+
+    return true;
+}
+
+/*
+ * Insertion functions (the opposite of extraction).  Yes for generating
+ * PAKs.
+ */
+bool pak_insert_one(pak_file_t *pak, const char *file) {
+    pak_directory_t dir;
+    unsigned char  *dat;
+    FILE           *fp;
+
+    /*
+     * We don't allow insertion on files that already exist within the
+     * pak file.  Weird shit can happen if we allow that ;). We also
+     * don't allow insertion if the pak isn't opened in write mode.  
+     */ 
+    if (!pak || !file || !pak->insert || pak_exists(pak, file, NULL))
+        return false;
+
+    if (!(fp = fopen(file, "rb")))
+        return false;
+
+    /*
+     * Calculate the total file length, since it will be wrote to
+     * the directory entry, and the actual contents of the file
+     * to the PAK file itself.
+     */
+    file_seek(fp, 0, SEEK_END);
+    dir.len = ftell(fp);
+    file_seek(fp, 0, SEEK_SET);
+
+    dir.pos = ftell(pak->handle);
+
+    /*
+     * Allocate some memory for loading in the data that will be
+     * redirected into the PAK file.
+     */   
+    if (!(dat = (unsigned char *)mem_a(dir.len))) {
+        file_close(fp);
+        return false;
+    }
+
+    file_read (dat, dir.len, 1, fp);
+    file_close(fp);
+    file_write(dat, dir.len, 1, pak->handle);
+
+    return true;
+}
+
+/*
+ * Like pak_insert_one, except this collects files in all directories
+ * from a root directory, and inserts them all.
+ */  
+bool pak_insert_all(pak_file_t *pak, const char *dir) {
+    DIR           *dp;
+    struct dirent *dirp;
+
+    if (!(pak->insert))
+        return false;
+
+    if (!(dp = opendir(dir)))
+        return false;
+
+    while ((dirp = readdir(dp))) {
+        if (!(pak_insert_one(pak, dirp->d_name))) {
+            closedir(dp);
+            return false;
+        }
+    }
+
+    closedir(dp);
+    return true;
+}
+
+bool pak_close(pak_file_t *pak) {
+    size_t itr;
+
+    if (!pak)
+        return false;
+
+    /*
+     * In insert mode we need to patch the header, and write
+     * our directory entries at the end of the file.
+     */  
+    if (pak->insert) {
+        pak->header.dirlen = vec_size(pak->directories) * 64;
+        pak->header.diroff = ftell(pak->handle);
+
+        /* patch header */ 
+        file_seek (pak->handle, 0, SEEK_SET);
+        file_write(&(pak->header), sizeof(pak_header_t), 1, pak->handle);
+
+        /* write directories */
+        file_seek (pak->handle, pak->header.diroff, SEEK_SET);
+
+        for (itr = 0; itr < vec_size(pak->directories); itr++) {
+            file_write(&(pak->directories[itr]), sizeof(pak_directory_t), 1, pak->handle);
+        }
+    }
+
+    vec_free  (pak->directories);
+    file_close(pak->handle);
+    mem_d     (pak);
+
+    return true;
+}