Make WIMStructs reference-counted
[wimlib] / src / wim.c
index 97e156d..e01131d 100644 (file)
--- a/src/wim.c
+++ b/src/wim.c
 /*
- * wim.c - Stuff that doesn't fit into any other file
+ * wim.c - High-level code dealing with WIMStructs and images.
  */
 
 /*
- * Copyright (C) 2012, 2013 Eric Biggers
+ * Copyright (C) 2012, 2013, 2014, 2015 Eric Biggers
  *
- * This file is part of wimlib, a library for working with WIM files.
+ * This file is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option) any
+ * later version.
  *
- * wimlib is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 3 of the License, or (at your option)
- * any later version.
- *
- * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
- * A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * This file is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  * details.
  *
- * You should have received a copy of the GNU General Public License
- * along with wimlib; if not, see http://www.gnu.org/licenses/.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this file; if not, see http://www.gnu.org/licenses/.
  */
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
 #endif
 
-#include "wimlib/error.h"
+#include <errno.h>
+#include <fcntl.h>
+#ifndef __WIN32__
+#  include <langinfo.h>
+#endif
+#include <pthread.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "wimlib.h"
+#include "wimlib/assert.h"
+#include "wimlib/blob_table.h"
 #include "wimlib/dentry.h"
 #include "wimlib/encoding.h"
 #include "wimlib/file_io.h"
 #include "wimlib/integrity.h"
-#include "wimlib/lookup_table.h"
 #include "wimlib/metadata.h"
-#ifdef WITH_NTFS_3G
-#  include "wimlib/ntfs_3g.h" /* for do_ntfs_umount() */
-#endif
+#include "wimlib/ntfs_3g.h" /* for libntfs3g_global_init() */
 #include "wimlib/security.h"
 #include "wimlib/wim.h"
 #include "wimlib/xml.h"
+#include "wimlib/win32.h"
+
+/* Information about the available compression types for the WIM format.  */
+static const struct {
+       const tchar *name;
+       u32 min_chunk_size;
+       u32 max_chunk_size;
+       u32 default_nonsolid_chunk_size;
+       u32 default_solid_chunk_size;
+} wim_ctype_info[] = {
+       [WIMLIB_COMPRESSION_TYPE_NONE] = {
+               .name = T("None"),
+               .min_chunk_size = 0,
+               .max_chunk_size = 0,
+               .default_nonsolid_chunk_size = 0,
+               .default_solid_chunk_size = 0,
+       },
+       [WIMLIB_COMPRESSION_TYPE_XPRESS] = {
+               .name = T("XPRESS"),
+               .min_chunk_size = 4096,
+               .max_chunk_size = 65536,
+               .default_nonsolid_chunk_size = 32768,
+               .default_solid_chunk_size = 32768,
+       },
+       [WIMLIB_COMPRESSION_TYPE_LZX] = {
+               .name = T("LZX"),
+               .min_chunk_size = 32768,
+               .max_chunk_size = 2097152,
+               .default_nonsolid_chunk_size = 32768,
+               .default_solid_chunk_size = 32768,
+       },
+       [WIMLIB_COMPRESSION_TYPE_LZMS] = {
+               .name = T("LZMS"),
+               .min_chunk_size = 32768,
+               .max_chunk_size = 1073741824,
+               .default_nonsolid_chunk_size = 131072,
+               .default_solid_chunk_size = 67108864,
+       },
+};
+
+/* Is the specified compression type valid?  */
+static bool
+wim_compression_type_valid(enum wimlib_compression_type ctype)
+{
+       return (unsigned)ctype < ARRAY_LEN(wim_ctype_info) &&
+              wim_ctype_info[(unsigned)ctype].name != NULL;
+}
 
-#ifdef __WIN32__
-#  include "wimlib/win32.h" /* for realpath() replacement */
-#endif
+/* Is the specified chunk size valid for the compression type?  */
+static bool
+wim_chunk_size_valid(u32 chunk_size, enum wimlib_compression_type ctype)
+{
+       if (!(chunk_size == 0 || is_power_of_2(chunk_size)))
+               return false;
 
-#include <errno.h>
-#include <fcntl.h>
-#ifndef __WIN32__
-#  include <langinfo.h>
-#endif
-#include <limits.h>
-#include <stdarg.h>
-#include <stdlib.h>
-#include <unistd.h>
+       return chunk_size >= wim_ctype_info[(unsigned)ctype].min_chunk_size &&
+              chunk_size <= wim_ctype_info[(unsigned)ctype].max_chunk_size;
+}
+
+/* Return the default chunk size to use for the specified compression type in
+ * non-solid resources.  */
+static u32
+wim_default_nonsolid_chunk_size(enum wimlib_compression_type ctype)
+{
+       return wim_ctype_info[(unsigned)ctype].default_nonsolid_chunk_size;
+}
+
+/* Return the default chunk size to use for the specified compression type in
+ * solid resources.  */
+static u32
+wim_default_solid_chunk_size(enum wimlib_compression_type ctype)
+{
+       return wim_ctype_info[(unsigned)ctype].default_solid_chunk_size;
+}
+
+/* Return the default compression type to use in solid resources.  */
+static enum wimlib_compression_type
+wim_default_solid_compression_type(void)
+{
+       return WIMLIB_COMPRESSION_TYPE_LZMS;
+}
 
 static int
-image_print_metadata(WIMStruct *wim)
+is_blob_in_solid_resource(struct blob_descriptor *blob, void *_ignore)
 {
-       DEBUG("Printing metadata for image %d", wim->current_image);
-       print_wim_security_data(wim_security_data(wim));
-       return for_dentry_in_tree(wim_root_dentry(wim), print_dentry,
-                                 wim->lookup_table);
+       return blob->blob_location == BLOB_IN_WIM &&
+               (blob->rdesc->flags & WIM_RESHDR_FLAG_SOLID);
 }
 
+bool
+wim_has_solid_resources(const WIMStruct *wim)
+{
+       return for_blob_in_table(wim->blob_table, is_blob_in_solid_resource, NULL);
+}
 
 static WIMStruct *
 new_wim_struct(void)
 {
        WIMStruct *wim = CALLOC(1, sizeof(WIMStruct));
-       if (wim) {
-               wim->in_fd.fd = -1;
-               wim->out_fd.fd = -1;
-               INIT_LIST_HEAD(&wim->subwims);
-       }
+       if (!wim)
+               return NULL;
+
+       wim->refcnt = 1;
+       filedes_invalidate(&wim->in_fd);
+       filedes_invalidate(&wim->out_fd);
+       wim->out_solid_compression_type = wim_default_solid_compression_type();
+       wim->out_solid_chunk_size = wim_default_solid_chunk_size(
+                                       wim->out_solid_compression_type);
        return wim;
 }
 
-/* Determine if the chunk size is valid for the specified compression type.  */
-static bool
-wim_chunk_size_valid(u32 chunk_size, int ctype)
+/* API function documented in wimlib.h  */
+WIMLIBAPI int
+wimlib_create_new_wim(enum wimlib_compression_type ctype, WIMStruct **wim_ret)
 {
-       u32 order;
+       int ret;
+       WIMStruct *wim;
 
-       /* Chunk size is meaningless for uncompressed WIMs --- any value is
-        * okay.  */
-       if (ctype == WIMLIB_COMPRESSION_TYPE_NONE)
-               return true;
+       ret = wimlib_global_init(WIMLIB_INIT_FLAG_ASSUME_UTF8);
+       if (ret)
+               return ret;
 
-       /* Chunk size must be power of 2.  */
-       if (chunk_size == 0)
-               return false;
-       order = bsr32(chunk_size);
-       if (chunk_size != 1U << order)
-               return false;
+       if (!wim_ret)
+               return WIMLIB_ERR_INVALID_PARAM;
 
-       /* Order        Size
-        * =====        ====
-        * 15           32768
-        * 16           65536
-        * 17           131072
-        * 18           262144
-        * 19           524288
-        * 20           1048576
-        * 21           2097152
-        * 22           4194304
-        * 23           8388608
-        * 24           16777216
-        * 25           33554432
-        * 26           67108864
-        */
-       switch (ctype) {
-       case WIMLIB_COMPRESSION_TYPE_LZX:
-               /* For LZX compression, the chunk size corresponds to the LZX
-                * window size, which according the LZX specification can be any
-                * power of 2 between 2^15 and 2^21, inclusively.  All these are
-                * supported by wimlib; however, unfortunately only 2^15 is
-                * supported by WIMGAPI[1] so this value is used by default.
-                *
-                * [1] WIMGAPI (Windows 7) attempts to decompress LZX chunk
-                * sizes > 2^15 but seems to have bug(s) that cause it to fail
-                * or crash.  (I tried several tweaks to the LZX data but none
-                * resulted in successful decompression.)  WIMGAPI (Windows 8)
-                * appears to refuse to open WIMs with chunk size > 2^15
-                * entirely.  */
-               return order >= 15 && order <= 21;
-
-       case WIMLIB_COMPRESSION_TYPE_XPRESS:
-               /* WIMGAPI (Windows 7) didn't seem to support XPRESS chunk size
-                * below 32768 bytes, but larger power-of-two sizes appear to be
-                * supported.  67108864 was the largest size that worked.
-                * (Note, however, that the offsets of XPRESS matches are still
-                * limited to 65535 bytes even when a much larger chunk size is
-                * used!)
-                *
-                * WIMGAPI (Windows 8) seemed to have removed the support for
-                * larger XPRESS chunk sizes and will refuse to open such WIMs.
-                *
-                * 2^15 = 32768 is the default value used for compatibility, but
-                * wimlib can actually use up to 2^26.  */
-               return order >= 15 && order <= 26;
+       if (!wim_compression_type_valid(ctype))
+               return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 
-       case WIMLIB_COMPRESSION_TYPE_LZMS:
-               return order >= 15 && order <= 26;
+       wim = new_wim_struct();
+       if (!wim)
+               return WIMLIB_ERR_NOMEM;
+
+       wim->xml_info = xml_new_info_struct();
+       wim->blob_table = new_blob_table(9001);
+       if (!wim->xml_info || !wim->blob_table) {
+               wimlib_free(wim);
+               return WIMLIB_ERR_NOMEM;
        }
-       return false;
+
+       /* Fill in wim->hdr with default values  */
+       wim->hdr.magic = WIM_MAGIC;
+       wim->hdr.wim_version = WIM_VERSION_DEFAULT;
+       wim->hdr.flags = 0;
+       wim->hdr.chunk_size = 0;
+       generate_guid(wim->hdr.guid);
+       wim->hdr.part_number = 1;
+       wim->hdr.total_parts = 1;
+       wim->hdr.image_count = 0;
+       wim->hdr.boot_idx = 0;
+
+       wim->compression_type = WIMLIB_COMPRESSION_TYPE_NONE;
+       wim->chunk_size = wim->hdr.chunk_size;
+
+       /* Set the output compression type  */
+       wim->out_compression_type = ctype;
+       wim->out_chunk_size = wim_default_nonsolid_chunk_size(ctype);
+
+       *wim_ret = wim;
+       return 0;
 }
 
-/* Return the default chunk size to use for the specified compression type.
- *
- * See notes above in wim_chunk_size_valid().  */
-static u32
-wim_default_chunk_size(int ctype)
+static void
+destroy_image_metadata(struct wim_image_metadata *imd,
+                      struct blob_table *table,
+                      bool free_metadata_blob_descriptor)
+{
+       free_dentry_tree(imd->root_dentry, table);
+       imd->root_dentry = NULL;
+       free_wim_security_data(imd->security_data);
+       imd->security_data = NULL;
+
+       if (free_metadata_blob_descriptor) {
+               free_blob_descriptor(imd->metadata_blob);
+               imd->metadata_blob = NULL;
+       }
+       if (!table) {
+               struct blob_descriptor *blob, *tmp;
+               list_for_each_entry_safe(blob, tmp, &imd->unhashed_blobs, unhashed_list)
+                       free_blob_descriptor(blob);
+       }
+       INIT_LIST_HEAD(&imd->unhashed_blobs);
+       INIT_HLIST_HEAD(&imd->inode_list);
+}
+
+void
+put_image_metadata(struct wim_image_metadata *imd, struct blob_table *table)
 {
-       switch (ctype) {
-       case WIMLIB_COMPRESSION_TYPE_LZMS:
-               return 131072;
-       default:
-               return 32768;
+       if (imd && --imd->refcnt == 0) {
+               destroy_image_metadata(imd, table, true);
+               FREE(imd);
        }
 }
 
-/*
- * Calls a function on images in the WIM.  If @image is WIMLIB_ALL_IMAGES, @visitor
- * is called on the WIM once for each image, with each image selected as the
- * current image in turn.  If @image is a certain image, @visitor is called on
- * the WIM only once, with that image selected.
- */
+/* Appends the specified image metadata structure to the array of image metadata
+ * for a WIM, and increments the image count. */
 int
-for_image(WIMStruct *wim, int image, int (*visitor)(WIMStruct *))
+append_image_metadata(WIMStruct *wim, struct wim_image_metadata *imd)
 {
-       int ret;
-       int start;
-       int end;
-       int i;
+       struct wim_image_metadata **imd_array;
 
-       if (image == WIMLIB_ALL_IMAGES) {
-               start = 1;
-               end = wim->hdr.image_count;
-       } else if (image >= 1 && image <= wim->hdr.image_count) {
-               start = image;
-               end = image;
-       } else {
-               return WIMLIB_ERR_INVALID_IMAGE;
-       }
-       for (i = start; i <= end; i++) {
-               ret = select_wim_image(wim, i);
-               if (ret != 0)
-                       return ret;
-               ret = visitor(wim);
-               if (ret != 0)
-                       return ret;
-       }
+       imd_array = REALLOC(wim->image_metadata,
+                           sizeof(wim->image_metadata[0]) * (wim->hdr.image_count + 1));
+
+       if (!imd_array)
+               return WIMLIB_ERR_NOMEM;
+       wim->image_metadata = imd_array;
+       imd_array[wim->hdr.image_count++] = imd;
        return 0;
 }
 
-/* API function documented in wimlib.h  */
-WIMLIBAPI int
-wimlib_create_new_wim(int ctype, WIMStruct **wim_ret)
+struct wim_image_metadata *
+new_image_metadata(void)
 {
-       WIMStruct *wim;
-       struct wim_lookup_table *table;
-       int ret;
-
-       wimlib_global_init(WIMLIB_INIT_FLAG_ASSUME_UTF8);
+       struct wim_image_metadata *imd;
 
-       DEBUG("Creating new WIM with %"TS" compression.",
-             wimlib_get_compression_type_string(ctype));
+       imd = CALLOC(1, sizeof(*imd));
+       if (imd) {
+               imd->refcnt = 1;
+               INIT_HLIST_HEAD(&imd->inode_list);
+               INIT_LIST_HEAD(&imd->unhashed_blobs);
+       }
+       return imd;
+}
 
-       /* Allocate the WIMStruct. */
-       wim = new_wim_struct();
-       if (wim == NULL)
-               return WIMLIB_ERR_NOMEM;
+static struct wim_image_metadata **
+new_image_metadata_array(unsigned num_images)
+{
+       struct wim_image_metadata **imd_array;
 
-       ret = init_wim_header(&wim->hdr, ctype, wim_default_chunk_size(ctype));
-       if (ret)
-               goto out_free;
+       imd_array = CALLOC(num_images, sizeof(imd_array[0]));
 
-       table = new_lookup_table(9001);
-       if (table == NULL) {
-               ret = WIMLIB_ERR_NOMEM;
-               goto out_free;
+       if (!imd_array)
+               return NULL;
+       for (unsigned i = 0; i < num_images; i++) {
+               imd_array[i] = new_image_metadata();
+               if (unlikely(!imd_array[i])) {
+                       for (unsigned j = 0; j < i; j++)
+                               put_image_metadata(imd_array[j], NULL);
+                       FREE(imd_array);
+                       return NULL;
+               }
        }
-       wim->lookup_table = table;
-       wim->refcnts_ok = 1;
-       wim->compression_type = ctype;
-       wim->out_compression_type = ctype;
-       wim->chunk_size = wim->hdr.chunk_size;
-       wim->out_chunk_size = wim->hdr.chunk_size;
-       *wim_ret = wim;
-       return 0;
-out_free:
-       FREE(wim);
-       return ret;
+       return imd_array;
 }
 
+
+/*
+ * Load the metadata for the specified WIM image into memory and set it
+ * as the WIMStruct's currently selected image.
+ *
+ * @wim
+ *     The WIMStruct for the WIM.
+ * @image
+ *     The 1-based index of the image in the WIM to select.
+ *
+ * On success, 0 will be returned, wim->current_image will be set to
+ * @image, and wim_get_current_image_metadata() can be used to retrieve
+ * metadata information for the image.
+ *
+ * On failure, WIMLIB_ERR_INVALID_IMAGE, WIMLIB_ERR_METADATA_NOT_FOUND,
+ * or another error code will be returned.
+ */
 int
 select_wim_image(WIMStruct *wim, int image)
 {
        struct wim_image_metadata *imd;
        int ret;
 
-       DEBUG("Selecting image %d", image);
-
-       if (image == WIMLIB_NO_IMAGE) {
-               ERROR("Invalid image: %d", WIMLIB_NO_IMAGE);
+       if (image == WIMLIB_NO_IMAGE)
                return WIMLIB_ERR_INVALID_IMAGE;
-       }
 
        if (image == wim->current_image)
                return 0;
 
-       if (image < 1 || image > wim->hdr.image_count) {
-               ERROR("Cannot select image %d: There are only %u images",
-                     image, wim->hdr.image_count);
+       if (image < 1 || image > wim->hdr.image_count)
                return WIMLIB_ERR_INVALID_IMAGE;
-       }
 
-       if (!wim_has_metadata(wim)) {
-               ERROR("\"%"TS"\" does not contain metadata resources!", wim->filename);
-               if (wim->hdr.part_number != 1)
-                       ERROR("Specify the first part of the split WIM instead.");
+       if (!wim_has_metadata(wim))
                return WIMLIB_ERR_METADATA_NOT_FOUND;
-       }
 
-       /* If a valid image is currently selected, it can be freed if it is not
-        * modified.  */
-       if (wim->current_image != WIMLIB_NO_IMAGE) {
-               imd = wim_get_current_image_metadata(wim);
-               if (!imd->modified) {
-                       wimlib_assert(list_empty(&imd->unhashed_streams));
-                       DEBUG("Freeing image %u", wim->current_image);
-                       destroy_image_metadata(imd, NULL, false);
-               }
-       }
+       /* If a valid image is currently selected, its metadata can be freed if
+        * it is not dirty and no other WIMStructs may have it selected.  */
+       deselect_current_wim_image(wim);
        wim->current_image = image;
        imd = wim_get_current_image_metadata(wim);
-       if (imd->root_dentry || imd->modified) {
+       if (imd->root_dentry || is_image_dirty(imd)) {
                ret = 0;
        } else {
-               #ifdef ENABLE_DEBUG
-               DEBUG("Reading metadata resource specified by the following "
-                     "lookup table entry:");
-               print_lookup_table_entry(imd->metadata_lte, stderr);
-               #endif
-               ret = read_metadata_resource(wim, imd);
+               ret = read_metadata_resource(imd);
                if (ret)
                        wim->current_image = WIMLIB_NO_IMAGE;
        }
        return ret;
 }
 
+void
+deselect_current_wim_image(WIMStruct *wim)
+{
+       struct wim_image_metadata *imd;
+       if (wim->current_image == WIMLIB_NO_IMAGE)
+               return;
+       imd = wim_get_current_image_metadata(wim);
+       if (!is_image_dirty(imd) && imd->refcnt == 1) {
+               wimlib_assert(list_empty(&imd->unhashed_blobs));
+               destroy_image_metadata(imd, NULL, false);
+       }
+       wim->current_image = WIMLIB_NO_IMAGE;
+}
 
-/* API function documented in wimlib.h  */
-WIMLIBAPI const tchar *
-wimlib_get_compression_type_string(int ctype)
+/*
+ * Calls a function on images in the WIM.  If @image is WIMLIB_ALL_IMAGES,
+ * @visitor is called on the WIM once for each image, with each image selected
+ * as the current image in turn.  If @image is a certain image, @visitor is
+ * called on the WIM only once, with that image selected.
+ */
+int
+for_image(WIMStruct *wim, int image, int (*visitor)(WIMStruct *))
 {
-       switch (ctype) {
-               case WIMLIB_COMPRESSION_TYPE_NONE:
-                       return T("None");
-               case WIMLIB_COMPRESSION_TYPE_LZX:
-                       return T("LZX");
-               case WIMLIB_COMPRESSION_TYPE_XPRESS:
-                       return T("XPRESS");
-               case WIMLIB_COMPRESSION_TYPE_LZMS:
-                       return T("LZMS");
-               default:
-                       return T("Invalid");
+       int ret;
+       int start;
+       int end;
+       int i;
+
+       if (image == WIMLIB_ALL_IMAGES) {
+               start = 1;
+               end = wim->hdr.image_count;
+       } else if (image >= 1 && image <= wim->hdr.image_count) {
+               start = image;
+               end = image;
+       } else {
+               return WIMLIB_ERR_INVALID_IMAGE;
        }
+       for (i = start; i <= end; i++) {
+               ret = select_wim_image(wim, i);
+               if (ret != 0)
+                       return ret;
+               ret = visitor(wim);
+               if (ret != 0)
+                       return ret;
+       }
+       return 0;
 }
 
 /* API function documented in wimlib.h  */
@@ -362,15 +441,7 @@ wimlib_print_available_images(const WIMStruct *wim, int image)
                tputchar(T('-'));
        tputchar(T('\n'));
        for (i = first; i <= last; i++)
-               print_image_info(wim->wim_info, i);
-}
-
-
-/* API function documented in wimlib.h  */
-WIMLIBAPI int
-wimlib_print_metadata(WIMStruct *wim, int image)
-{
-       return for_image(wim, image, image_print_metadata);
+               xml_print_image_info(wim->xml_info, i);
 }
 
 /* API function documented in wimlib.h  */
@@ -378,15 +449,15 @@ WIMLIBAPI int
 wimlib_get_wim_info(WIMStruct *wim, struct wimlib_wim_info *info)
 {
        memset(info, 0, sizeof(struct wimlib_wim_info));
-       memcpy(info->guid, wim->hdr.guid, WIMLIB_GUID_LEN);
+       copy_guid(info->guid, wim->hdr.guid);
        info->image_count = wim->hdr.image_count;
        info->boot_index = wim->hdr.boot_idx;
        info->wim_version = wim->hdr.wim_version;
-       info->chunk_size = wim->hdr.chunk_size;
+       info->chunk_size = wim->chunk_size;
        info->part_number = wim->hdr.part_number;
        info->total_parts = wim->hdr.total_parts;
        info->compression_type = wim->compression_type;
-       info->total_bytes = wim_info_get_total_bytes(wim->wim_info);
+       info->total_bytes = xml_get_total_bytes(wim->xml_info);
        info->has_integrity_table = wim_has_integrity_table(wim);
        info->opened_from_file = (wim->filename != NULL);
        info->is_readonly = (wim->hdr.flags & WIM_HDR_FLAG_READONLY) ||
@@ -406,7 +477,15 @@ wimlib_get_wim_info(WIMStruct *wim, struct wimlib_wim_info *info)
 WIMLIBAPI int
 wimlib_set_wim_info(WIMStruct *wim, const struct wimlib_wim_info *info, int which)
 {
-       int ret;
+       if (which & ~(WIMLIB_CHANGE_READONLY_FLAG |
+                     WIMLIB_CHANGE_GUID |
+                     WIMLIB_CHANGE_BOOT_INDEX |
+                     WIMLIB_CHANGE_RPFIX_FLAG))
+               return WIMLIB_ERR_INVALID_PARAM;
+
+       if ((which & WIMLIB_CHANGE_BOOT_INDEX) &&
+           info->boot_index > wim->hdr.image_count)
+               return WIMLIB_ERR_INVALID_IMAGE;
 
        if (which & WIMLIB_CHANGE_READONLY_FLAG) {
                if (info->is_marked_readonly)
@@ -415,26 +494,11 @@ wimlib_set_wim_info(WIMStruct *wim, const struct wimlib_wim_info *info, int whic
                        wim->hdr.flags &= ~WIM_HDR_FLAG_READONLY;
        }
 
-       if ((which & ~WIMLIB_CHANGE_READONLY_FLAG) == 0)
-               return 0;
-
-       ret = can_modify_wim(wim);
-       if (ret)
-               return ret;
+       if (which & WIMLIB_CHANGE_GUID)
+               copy_guid(wim->hdr.guid, info->guid);
 
-       if (which & WIMLIB_CHANGE_GUID) {
-               memcpy(wim->hdr.guid, info->guid, WIM_GID_LEN);
-               wim->guid_set_explicitly = 1;
-       }
-
-       if (which & WIMLIB_CHANGE_BOOT_INDEX) {
-               if (info->boot_index > wim->hdr.image_count) {
-                       ERROR("%u is not 0 or a valid image in the WIM to mark as bootable",
-                             info->boot_index);
-                       return WIMLIB_ERR_INVALID_IMAGE;
-               }
+       if (which & WIMLIB_CHANGE_BOOT_INDEX)
                wim->hdr.boot_idx = info->boot_index;
-       }
 
        if (which & WIMLIB_CHANGE_RPFIX_FLAG) {
                if (info->has_rpfix)
@@ -447,64 +511,95 @@ wimlib_set_wim_info(WIMStruct *wim, const struct wimlib_wim_info *info, int whic
 
 /* API function documented in wimlib.h  */
 WIMLIBAPI int
-wimlib_set_output_compression_type(WIMStruct *wim, int ctype)
-{
-       switch (ctype) {
-       case WIMLIB_COMPRESSION_TYPE_INVALID:
-               break;
-       case WIMLIB_COMPRESSION_TYPE_NONE:
-       case WIMLIB_COMPRESSION_TYPE_LZX:
-       case WIMLIB_COMPRESSION_TYPE_XPRESS:
-       case WIMLIB_COMPRESSION_TYPE_LZMS:
-               wim->out_compression_type = ctype;
-
-               /* Reset the chunk size if it's no longer valid.  */
-               if (!wim_chunk_size_valid(wim->out_chunk_size,
-                                         wim->out_compression_type))
-                       wim->out_chunk_size = wim_default_chunk_size(wim->out_compression_type);
+wimlib_set_output_compression_type(WIMStruct *wim,
+                                  enum wimlib_compression_type ctype)
+{
+       if (!wim_compression_type_valid(ctype))
+               return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
+
+       wim->out_compression_type = ctype;
+
+       /* Reset the chunk size if it's no longer valid.  */
+       if (!wim_chunk_size_valid(wim->out_chunk_size, ctype))
+               wim->out_chunk_size = wim_default_nonsolid_chunk_size(ctype);
+       return 0;
+}
+
+/* API function documented in wimlib.h  */
+WIMLIBAPI int
+wimlib_set_output_pack_compression_type(WIMStruct *wim,
+                                       enum wimlib_compression_type ctype)
+{
+       if (!wim_compression_type_valid(ctype))
+               return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
+
+       /* Solid resources can't be uncompressed.  */
+       if (ctype == WIMLIB_COMPRESSION_TYPE_NONE)
+               return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
+
+       wim->out_solid_compression_type = ctype;
+
+       /* Reset the chunk size if it's no longer valid.  */
+       if (!wim_chunk_size_valid(wim->out_solid_chunk_size, ctype))
+               wim->out_solid_chunk_size = wim_default_solid_chunk_size(ctype);
+       return 0;
+}
+
+/* API function documented in wimlib.h  */
+WIMLIBAPI int
+wimlib_set_output_chunk_size(WIMStruct *wim, u32 chunk_size)
+{
+       if (chunk_size == 0) {
+               wim->out_chunk_size =
+                       wim_default_nonsolid_chunk_size(wim->out_compression_type);
                return 0;
        }
-       return WIMLIB_ERR_INVALID_PARAM;
+
+       if (!wim_chunk_size_valid(chunk_size, wim->out_compression_type))
+               return WIMLIB_ERR_INVALID_CHUNK_SIZE;
+
+       wim->out_chunk_size = chunk_size;
+       return 0;
 }
 
 /* API function documented in wimlib.h  */
 WIMLIBAPI int
-wimlib_set_output_chunk_size(WIMStruct *wim, uint32_t chunk_size)
+wimlib_set_output_pack_chunk_size(WIMStruct *wim, u32 chunk_size)
 {
-       if (!wim_chunk_size_valid(chunk_size, wim->out_compression_type)) {
-               ERROR("Invalid chunk size (%"PRIu32" bytes) "
-                     "for compression type %"TS"!",
-                     chunk_size,
-                     wimlib_get_compression_type_string(wim->out_compression_type));
-               switch (wim->out_compression_type) {
-               case WIMLIB_COMPRESSION_TYPE_XPRESS:
-                       ERROR("Valid chunk sizes for XPRESS are "
-                             "32768, 65536, 131072, ..., 67108864.");
-                       break;
-               case WIMLIB_COMPRESSION_TYPE_LZX:
-                       ERROR("Valid chunk sizes for LZX are "
-                             "32768, 65536, 131072, ..., 2097152.");
-                       break;
-               case WIMLIB_COMPRESSION_TYPE_LZMS:
-                       ERROR("Valid chunk sizes for LZMS are "
-                             "32768, 65536, 131072, ..., 67108864.");
-                       break;
-               }
-               return WIMLIB_ERR_INVALID_CHUNK_SIZE;
-       }
-       if (chunk_size != 32768 &&
-           wim->out_compression_type != WIMLIB_COMPRESSION_TYPE_LZMS)
-       {
-               WARNING  ("Changing the compression chunk size to any value other than\n"
-               "          the default of 32768 bytes eliminates compatibility with\n"
-               "          Microsoft's software!");
+       if (chunk_size == 0) {
+               wim->out_solid_chunk_size =
+                       wim_default_solid_chunk_size(wim->out_solid_compression_type);
+               return 0;
        }
-       wim->out_chunk_size = chunk_size;
+
+       if (!wim_chunk_size_valid(chunk_size, wim->out_solid_compression_type))
+               return WIMLIB_ERR_INVALID_CHUNK_SIZE;
+
+       wim->out_solid_chunk_size = chunk_size;
        return 0;
 }
 
+/* API function documented in wimlib.h  */
+WIMLIBAPI const tchar *
+wimlib_get_compression_type_string(enum wimlib_compression_type ctype)
+{
+       if (!wim_compression_type_valid(ctype))
+               return T("Invalid");
+
+       return wim_ctype_info[(unsigned)ctype].name;
+}
+
+WIMLIBAPI void
+wimlib_register_progress_function(WIMStruct *wim,
+                                 wimlib_progress_func_t progfunc,
+                                 void *progctx)
+{
+       wim->progfunc = progfunc;
+       wim->progctx = progctx;
+}
+
 static int
-do_open_wim(const tchar *filename, struct filedes *fd_ret)
+open_wim_file(const tchar *filename, struct filedes *fd_ret)
 {
        int raw_fd;
 
@@ -517,33 +612,14 @@ do_open_wim(const tchar *filename, struct filedes *fd_ret)
        return 0;
 }
 
-int
-reopen_wim(WIMStruct *wim)
-{
-       wimlib_assert(!filedes_valid(&wim->in_fd));
-       return do_open_wim(wim->filename, &wim->in_fd);
-}
-
-int
-close_wim(WIMStruct *wim)
-{
-       if (filedes_valid(&wim->in_fd)) {
-               filedes_close(&wim->in_fd);
-               filedes_invalidate(&wim->in_fd);
-       }
-       return 0;
-}
-
 /*
  * Begins the reading of a WIM file; opens the file and reads its header and
- * lookup table, and optionally checks the integrity.
+ * blob table, and optionally checks the integrity.
  */
 static int
-begin_read(WIMStruct *wim, const void *wim_filename_or_fd,
-          int open_flags, wimlib_progress_func_t progress_func)
+begin_read(WIMStruct *wim, const void *wim_filename_or_fd, int open_flags)
 {
        int ret;
-       int xml_num_images;
        const tchar *wimfile;
 
        if (open_flags & WIMLIB_OPEN_FLAG_FROM_PIPE) {
@@ -552,7 +628,7 @@ begin_read(WIMStruct *wim, const void *wim_filename_or_fd,
                wim->in_fd.is_pipe = 1;
        } else {
                wimfile = wim_filename_or_fd;
-               ret = do_open_wim(wimfile, &wim->in_fd);
+               ret = open_wim_file(wimfile, &wim->in_fd);
                if (ret)
                        return ret;
 
@@ -569,12 +645,13 @@ begin_read(WIMStruct *wim, const void *wim_filename_or_fd,
                 * replacement function in win32_replacements.c.
                 */
                wim->filename = realpath(wimfile, NULL);
-               if (wim->filename == NULL) {
-                       ERROR_WITH_ERRNO("Failed to resolve WIM filename");
+               if (!wim->filename) {
+                       ERROR_WITH_ERRNO("Failed to get full path to file "
+                                        "\"%"TS"\"", wimfile);
                        if (errno == ENOMEM)
                                return WIMLIB_ERR_NOMEM;
                        else
-                               return WIMLIB_ERR_OPEN;
+                               return WIMLIB_ERR_NO_FILENAME;
                }
        }
 
@@ -599,13 +676,9 @@ begin_read(WIMStruct *wim, const void *wim_filename_or_fd,
            (wim->hdr.total_parts != 1))
                return WIMLIB_ERR_IS_SPLIT_WIM;
 
-       DEBUG("According to header, WIM contains %u images", wim->hdr.image_count);
-
        /* If the boot index is invalid, print a warning and set it to 0 */
        if (wim->hdr.boot_idx > wim->hdr.image_count) {
-               WARNING("In `%"TS"', image %u is marked as bootable, "
-                       "but there are only %u images in the WIM",
-                       wimfile, wim->hdr.boot_idx, wim->hdr.image_count);
+               WARNING("Ignoring invalid boot index.");
                wim->hdr.boot_idx = 0;
        }
 
@@ -613,14 +686,12 @@ begin_read(WIMStruct *wim, const void *wim_filename_or_fd,
        if (wim->hdr.flags & WIM_HDR_FLAG_COMPRESSION) {
                if (wim->hdr.flags & WIM_HDR_FLAG_COMPRESS_LZX) {
                        wim->compression_type = WIMLIB_COMPRESSION_TYPE_LZX;
-               } else if (wim->hdr.flags & WIM_HDR_FLAG_COMPRESS_XPRESS) {
+               } else if (wim->hdr.flags & (WIM_HDR_FLAG_COMPRESS_XPRESS |
+                                            WIM_HDR_FLAG_COMPRESS_XPRESS_2)) {
                        wim->compression_type = WIMLIB_COMPRESSION_TYPE_XPRESS;
                } else if (wim->hdr.flags & WIM_HDR_FLAG_COMPRESS_LZMS) {
                        wim->compression_type = WIMLIB_COMPRESSION_TYPE_LZMS;
                } else {
-                       ERROR("The compression flag is set on \"%"TS"\", but "
-                             "a flag for a recognized format is not",
-                             wimfile);
                        return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
                }
        } else {
@@ -629,22 +700,22 @@ begin_read(WIMStruct *wim, const void *wim_filename_or_fd,
        wim->out_compression_type = wim->compression_type;
 
        /* Check and cache the chunk size.  */
-       wim->chunk_size = wim->out_chunk_size = wim->hdr.chunk_size;
+       wim->chunk_size = wim->hdr.chunk_size;
+       wim->out_chunk_size = wim->chunk_size;
        if (!wim_chunk_size_valid(wim->chunk_size, wim->compression_type)) {
                ERROR("Invalid chunk size (%"PRIu32" bytes) "
-                     "for compression type %"TS"!",
-                     wim->chunk_size,
+                     "for compression type %"TS"!", wim->chunk_size,
                      wimlib_get_compression_type_string(wim->compression_type));
                return WIMLIB_ERR_INVALID_CHUNK_SIZE;
        }
 
        if (open_flags & WIMLIB_OPEN_FLAG_CHECK_INTEGRITY) {
-               ret = check_wim_integrity(wim, progress_func);
+               ret = check_wim_integrity(wim);
                if (ret == WIM_INTEGRITY_NONEXISTENT) {
-                       WARNING("No integrity information for `%"TS"'; skipping "
-                               "integrity check.", wimfile);
+                       WARNING("\"%"TS"\" does not contain integrity "
+                               "information.  Skipping integrity check.",
+                               wimfile);
                } else if (ret == WIM_INTEGRITY_NOT_OK) {
-                       ERROR("WIM is not intact! (Failed integrity check)");
                        return WIMLIB_ERR_INTEGRITY;
                } else if (ret != WIM_INTEGRITY_OK) {
                        return ret;
@@ -653,202 +724,112 @@ begin_read(WIMStruct *wim, const void *wim_filename_or_fd,
 
        if (wim->hdr.image_count != 0 && wim->hdr.part_number == 1) {
                wim->image_metadata = new_image_metadata_array(wim->hdr.image_count);
-               if (wim->image_metadata == NULL)
+               if (!wim->image_metadata)
                        return WIMLIB_ERR_NOMEM;
        }
 
        if (open_flags & WIMLIB_OPEN_FLAG_FROM_PIPE) {
-               wim->lookup_table = new_lookup_table(9001);
-               if (wim->lookup_table == NULL)
+               wim->blob_table = new_blob_table(9001);
+               if (!wim->blob_table)
                        return WIMLIB_ERR_NOMEM;
        } else {
-               ret = read_wim_lookup_table(wim);
-               if (ret)
-                       return ret;
+               if (wim->hdr.blob_table_reshdr.uncompressed_size == 0 &&
+                   wim->hdr.xml_data_reshdr.uncompressed_size == 0)
+                       return WIMLIB_ERR_WIM_IS_INCOMPLETE;
 
                ret = read_wim_xml_data(wim);
                if (ret)
                        return ret;
 
-               xml_num_images = wim_info_get_num_images(wim->wim_info);
-               if (xml_num_images != wim->hdr.image_count) {
-                       ERROR("In the file `%"TS"', there are %u <IMAGE> elements "
-                             "in the XML data,", wimfile, xml_num_images);
-                       ERROR("but %u images in the WIM!  There must be exactly one "
-                             "<IMAGE> element per image.", wim->hdr.image_count);
+               if (xml_get_image_count(wim->xml_info) != wim->hdr.image_count) {
+                       ERROR("The WIM's header is inconsistent with its XML data.\n"
+                             "        Please submit a bug report if you believe this "
+                             "WIM file should be considered valid.");
                        return WIMLIB_ERR_IMAGE_COUNT;
                }
-               DEBUG("Done beginning read of WIM file `%"TS"'.", wimfile);
+
+               ret = read_blob_table(wim);
+               if (ret)
+                       return ret;
        }
        return 0;
 }
 
 int
 open_wim_as_WIMStruct(const void *wim_filename_or_fd, int open_flags,
-                     WIMStruct **wim_ret, wimlib_progress_func_t progress_func)
+                     WIMStruct **wim_ret,
+                     wimlib_progress_func_t progfunc, void *progctx)
 {
        WIMStruct *wim;
        int ret;
 
-       if (open_flags & WIMLIB_OPEN_FLAG_FROM_PIPE)
-               DEBUG("Opening pipable WIM from file descriptor %d.", *(const int*)wim_filename_or_fd);
-       else
-               DEBUG("Opening WIM file \"%"TS"\"", (const tchar*)wim_filename_or_fd);
-
-       wimlib_global_init(WIMLIB_INIT_FLAG_ASSUME_UTF8);
-
-       if (wim_ret == NULL)
-               return WIMLIB_ERR_INVALID_PARAM;
+       ret = wimlib_global_init(WIMLIB_INIT_FLAG_ASSUME_UTF8);
+       if (ret)
+               return ret;
 
        wim = new_wim_struct();
-       if (wim == NULL)
+       if (!wim)
                return WIMLIB_ERR_NOMEM;
 
-       ret = begin_read(wim, wim_filename_or_fd, open_flags, progress_func);
+       wim->progfunc = progfunc;
+       wim->progctx = progctx;
+
+       ret = begin_read(wim, wim_filename_or_fd, open_flags);
        if (ret) {
                wimlib_free(wim);
                return ret;
        }
 
-       DEBUG("Successfully opened WIM and created WIMStruct.");
        *wim_ret = wim;
        return 0;
 }
 
 /* API function documented in wimlib.h  */
 WIMLIBAPI int
-wimlib_open_wim(const tchar *wimfile, int open_flags,
-               WIMStruct **wim_ret, wimlib_progress_func_t progress_func)
-{
-       open_flags &= WIMLIB_OPEN_MASK_PUBLIC;
-       return open_wim_as_WIMStruct(wimfile, open_flags, wim_ret,
-                                    progress_func);
-}
-
-void
-destroy_image_metadata(struct wim_image_metadata *imd,
-                      struct wim_lookup_table *table,
-                      bool free_metadata_lte)
-{
-       free_dentry_tree(imd->root_dentry, table);
-       imd->root_dentry = NULL;
-       free_wim_security_data(imd->security_data);
-       imd->security_data = NULL;
-
-       if (free_metadata_lte) {
-               free_lookup_table_entry(imd->metadata_lte);
-               imd->metadata_lte = NULL;
-       }
-       if (table == NULL) {
-               struct wim_lookup_table_entry *lte, *tmp;
-               list_for_each_entry_safe(lte, tmp, &imd->unhashed_streams, unhashed_list)
-                       free_lookup_table_entry(lte);
-       }
-       INIT_LIST_HEAD(&imd->unhashed_streams);
-       INIT_LIST_HEAD(&imd->inode_list);
-#ifdef WITH_NTFS_3G
-       if (imd->ntfs_vol) {
-               do_ntfs_umount(imd->ntfs_vol);
-               imd->ntfs_vol = NULL;
-       }
-#endif
-}
-
-void
-put_image_metadata(struct wim_image_metadata *imd,
-                  struct wim_lookup_table *table)
+wimlib_open_wim_with_progress(const tchar *wimfile, int open_flags,
+                             WIMStruct **wim_ret,
+                             wimlib_progress_func_t progfunc, void *progctx)
 {
-       if (imd && --imd->refcnt == 0) {
-               destroy_image_metadata(imd, table, true);
-               FREE(imd);
-       }
-}
-
-/* Appends the specified image metadata structure to the array of image metadata
- * for a WIM, and increments the image count. */
-int
-append_image_metadata(WIMStruct *wim, struct wim_image_metadata *imd)
-{
-       struct wim_image_metadata **imd_array;
-
-       DEBUG("Reallocating image metadata array for image_count = %u",
-             wim->hdr.image_count + 1);
-       imd_array = REALLOC(wim->image_metadata,
-                           sizeof(wim->image_metadata[0]) * (wim->hdr.image_count + 1));
-
-       if (imd_array == NULL)
-               return WIMLIB_ERR_NOMEM;
-       wim->image_metadata = imd_array;
-       imd_array[wim->hdr.image_count++] = imd;
-       return 0;
-}
-
+       if (open_flags & ~(WIMLIB_OPEN_FLAG_CHECK_INTEGRITY |
+                          WIMLIB_OPEN_FLAG_ERROR_IF_SPLIT |
+                          WIMLIB_OPEN_FLAG_WRITE_ACCESS))
+               return WIMLIB_ERR_INVALID_PARAM;
 
-struct wim_image_metadata *
-new_image_metadata(void)
-{
-       struct wim_image_metadata *imd;
+       if (!wimfile || !*wimfile || !wim_ret)
+               return WIMLIB_ERR_INVALID_PARAM;
 
-       imd = CALLOC(1, sizeof(*imd));
-       if (imd) {
-               imd->refcnt = 1;
-               INIT_LIST_HEAD(&imd->inode_list);
-               INIT_LIST_HEAD(&imd->unhashed_streams);
-               DEBUG("Created new image metadata (refcnt=1)");
-       } else {
-               ERROR_WITH_ERRNO("Failed to allocate new image metadata structure");
-       }
-       return imd;
+       return open_wim_as_WIMStruct(wimfile, open_flags, wim_ret,
+                                    progfunc, progctx);
 }
 
-struct wim_image_metadata **
-new_image_metadata_array(unsigned num_images)
+/* API function documented in wimlib.h  */
+WIMLIBAPI int
+wimlib_open_wim(const tchar *wimfile, int open_flags, WIMStruct **wim_ret)
 {
-       struct wim_image_metadata **imd_array;
-
-       DEBUG("Creating new image metadata array for %u images",
-             num_images);
-
-       imd_array = CALLOC(num_images, sizeof(imd_array[0]));
-
-       if (imd_array == NULL) {
-               ERROR("Failed to allocate memory for %u image metadata structures",
-                     num_images);
-               return NULL;
-       }
-       for (unsigned i = 0; i < num_images; i++) {
-               imd_array[i] = new_image_metadata();
-               if (imd_array[i] == NULL) {
-                       for (unsigned j = 0; j < i; j++)
-                               put_image_metadata(imd_array[j], NULL);
-                       FREE(imd_array);
-                       return NULL;
-               }
-       }
-       return imd_array;
+       return wimlib_open_wim_with_progress(wimfile, open_flags, wim_ret,
+                                            NULL, NULL);
 }
 
-/* Checksum all streams that are unhashed (other than the metadata streams),
- * merging them into the lookup table as needed.  This is a no-op unless the
- * library has previously used to add or mount an image using the same
- * WIMStruct. */
+/* Checksum all blobs that are unhashed (other than the metadata blobs), merging
+ * them into the blob table as needed.  This is a no-op unless files have been
+ * added to an image in the same WIMStruct.  */
 int
-wim_checksum_unhashed_streams(WIMStruct *wim)
+wim_checksum_unhashed_blobs(WIMStruct *wim)
 {
        int ret;
 
        if (!wim_has_metadata(wim))
                return 0;
        for (int i = 0; i < wim->hdr.image_count; i++) {
-               struct wim_lookup_table_entry *lte, *tmp;
+               struct blob_descriptor *blob, *tmp;
                struct wim_image_metadata *imd = wim->image_metadata[i];
-               image_for_each_unhashed_stream_safe(lte, tmp, imd) {
-                       struct wim_lookup_table_entry *new_lte;
-                       ret = hash_unhashed_stream(lte, wim->lookup_table, &new_lte);
+               image_for_each_unhashed_blob_safe(blob, tmp, imd) {
+                       struct blob_descriptor *new_blob;
+                       ret = hash_unhashed_blob(blob, wim->blob_table, &new_blob);
                        if (ret)
                                return ret;
-                       if (new_lte != lte)
-                               free_lookup_table_entry(lte);
+                       if (new_blob != blob)
+                               free_blob_descriptor(blob);
                }
        }
        return 0;
@@ -886,69 +867,43 @@ can_modify_wim(WIMStruct *wim)
        return 0;
 }
 
-/*
- * can_delete_from_wim - Check if files or images can be deleted from a given
- * WIM file.
- *
- * This theoretically should be exactly the same as can_modify_wim(), but
- * unfortunately, due to bugs in Microsoft's software that generate incorrect
- * reference counts for some WIM resources, we need to run expensive
- * verifications to make sure the reference counts are correct on all WIM
- * resources.  Otherwise we might delete a WIM resource whose reference count
- * has fallen to 0, but is actually still referenced somewhere.
- */
-int
-can_delete_from_wim(WIMStruct *wim)
+/* Free a WIMStruct after no more resources reference it.  */
+void
+finalize_wim_struct(WIMStruct *wim)
 {
-       int ret;
-
-       ret = can_modify_wim(wim);
-       if (ret)
-               return ret;
-       if (!wim->refcnts_ok) {
-               ret = wim_recalculate_refcnts(wim);
-               if (ret)
-                       return ret;
-       }
-       return 0;
+       if (filedes_valid(&wim->in_fd))
+               filedes_close(&wim->in_fd);
+       if (filedes_valid(&wim->out_fd))
+               filedes_close(&wim->out_fd);
+       wimlib_free_decompressor(wim->decompressor);
+       xml_free_info_struct(wim->xml_info);
+       FREE(wim->filename);
+       FREE(wim);
 }
 
 /* API function documented in wimlib.h  */
 WIMLIBAPI void
 wimlib_free(WIMStruct *wim)
 {
-       if (wim == NULL)
+       if (!wim)
                return;
 
-       DEBUG("Freeing WIMStruct (filename=\"%"TS"\", image_count=%u)",
-             wim->filename, wim->hdr.image_count);
-
-       while (!list_empty(&wim->subwims)) {
-               WIMStruct *subwim;
-
-               subwim = list_entry(wim->subwims.next, WIMStruct, subwim_node);
-               list_del(&subwim->subwim_node);
-               DEBUG("Freeing subwim.");
-               wimlib_free(subwim);
-       }
-
-       if (filedes_valid(&wim->in_fd))
-               filedes_close(&wim->in_fd);
-       if (filedes_valid(&wim->out_fd))
-               filedes_close(&wim->out_fd);
-
-       wimlib_lzx_free_context(wim->lzx_context);
+       /* The blob table and image metadata are freed immediately, but other
+        * members of the WIMStruct such as the input file descriptor are
+        * retained until no more exported resources reference the WIMStruct. */
 
-       free_lookup_table(wim->lookup_table);
-
-       FREE(wim->filename);
-       free_wim_info(wim->wim_info);
-       if (wim->image_metadata) {
-               for (unsigned i = 0; i < wim->hdr.image_count; i++)
+       free_blob_table(wim->blob_table);
+       wim->blob_table = NULL;
+       if (wim->image_metadata != NULL) {
+               for (int i = 0; i < wim->hdr.image_count; i++)
                        put_image_metadata(wim->image_metadata[i], NULL);
                FREE(wim->image_metadata);
+               wim->image_metadata = NULL;
        }
-       FREE(wim);
+
+       wimlib_assert(wim->refcnt > 0);
+       if (--wim->refcnt == 0)
+               finalize_wim_struct(wim);
 }
 
 static bool
@@ -967,15 +922,53 @@ test_locale_ctype_utf8(void)
 }
 
 /* API function documented in wimlib.h  */
+WIMLIBAPI u32
+wimlib_get_version(void)
+{
+       return (WIMLIB_MAJOR_VERSION << 20) |
+              (WIMLIB_MINOR_VERSION << 10) |
+               WIMLIB_PATCH_VERSION;
+}
+
+static bool lib_initialized = false;
+static pthread_mutex_t lib_initialization_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+/* API function documented in wimlib.h  */
 WIMLIBAPI int
 wimlib_global_init(int init_flags)
 {
-       static bool already_inited = false;
-       int ret;
+       int ret = 0;
 
-       if (already_inited)
-               return 0;
-       libxml_global_init();
+       if (lib_initialized)
+               goto out;
+
+       pthread_mutex_lock(&lib_initialization_mutex);
+
+       if (lib_initialized)
+               goto out_unlock;
+
+#ifdef ENABLE_ERROR_MESSAGES
+       if (!wimlib_error_file)
+               wimlib_error_file = stderr;
+#endif
+
+       ret = WIMLIB_ERR_INVALID_PARAM;
+       if (init_flags & ~(WIMLIB_INIT_FLAG_ASSUME_UTF8 |
+                          WIMLIB_INIT_FLAG_DONT_ACQUIRE_PRIVILEGES |
+                          WIMLIB_INIT_FLAG_STRICT_CAPTURE_PRIVILEGES |
+                          WIMLIB_INIT_FLAG_STRICT_APPLY_PRIVILEGES |
+                          WIMLIB_INIT_FLAG_DEFAULT_CASE_SENSITIVE |
+                          WIMLIB_INIT_FLAG_DEFAULT_CASE_INSENSITIVE))
+               goto out_unlock;
+
+       ret = WIMLIB_ERR_INVALID_PARAM;
+       if ((init_flags & (WIMLIB_INIT_FLAG_DEFAULT_CASE_SENSITIVE |
+                          WIMLIB_INIT_FLAG_DEFAULT_CASE_INSENSITIVE))
+                       == (WIMLIB_INIT_FLAG_DEFAULT_CASE_SENSITIVE |
+                           WIMLIB_INIT_FLAG_DEFAULT_CASE_INSENSITIVE))
+               goto out_unlock;
+
+       xml_global_init();
        if (!(init_flags & WIMLIB_INIT_FLAG_ASSUME_UTF8)) {
                wimlib_mbs_is_utf8 = test_locale_ctype_utf8();
        #ifdef WITH_NTFS_3G
@@ -986,11 +979,19 @@ wimlib_global_init(int init_flags)
 #ifdef __WIN32__
        ret = win32_global_init(init_flags);
        if (ret)
-               return ret;
-#else
-       ret = 0;
+               goto out_unlock;
 #endif
-       already_inited = true;
+       iconv_global_init();
+       init_upcase();
+       if (init_flags & WIMLIB_INIT_FLAG_DEFAULT_CASE_SENSITIVE)
+               default_ignore_case = false;
+       else if (init_flags & WIMLIB_INIT_FLAG_DEFAULT_CASE_INSENSITIVE)
+               default_ignore_case = true;
+       lib_initialized = true;
+       ret = 0;
+out_unlock:
+       pthread_mutex_unlock(&lib_initialization_mutex);
+out:
        return ret;
 }
 
@@ -998,9 +999,23 @@ wimlib_global_init(int init_flags)
 WIMLIBAPI void
 wimlib_global_cleanup(void)
 {
-       libxml_global_cleanup();
+       if (!lib_initialized)
+               return;
+
+       pthread_mutex_lock(&lib_initialization_mutex);
+
+       if (!lib_initialized)
+               goto out_unlock;
+
+       xml_global_cleanup();
        iconv_global_cleanup();
 #ifdef __WIN32__
        win32_global_cleanup();
 #endif
+
+       wimlib_set_error_file(NULL);
+       lib_initialized = false;
+
+out_unlock:
+       pthread_mutex_unlock(&lib_initialization_mutex);
 }