/*

 * Copyright © 2009  Red Hat, Inc.

 * Copyright © 2018  Ebrahim Byagowi

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Red Hat Author(s): Behdad Esfahbod

 */

#include "hb.hh"

#include "hb-blob.hh"

#ifdef HAVE_SYS_MMAN_H

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif /* HAVE_UNISTD_H */

#include <sys/mman.h>

#endif /* HAVE_SYS_MMAN_H */

/**

 * SECTION: hb-blob

 * @title: hb-blob

 * @short_description: Binary data containers

 * @include: hb.h

 *

 * Blobs wrap a chunk of binary data to handle lifecycle management of data

 * while it is passed between client and HarfBuzz.  Blobs are primarily used

 * to create font faces, but also to access font face tables, as well as

 * pass around other binary data.

 **/

/**

 * hb_blob_create: (skip)

 * @data: Pointer to blob data.

 * @length: Length of @data in bytes.

 * @mode: Memory mode for @data.

 * @user_data: Data parameter to pass to @destroy.

 * @destroy: (nullable): Callback to call when @data is not needed anymore.

 *

 * Creates a new "blob" object wrapping @data.  The @mode parameter is used

 * to negotiate ownership and lifecycle of @data.

 *

 * Return value: New blob, or the empty blob if something failed or if @length is

 * zero.  Destroy with hb_blob_destroy().

 *

 * Since: 0.9.2

 **/

hb_blob_t *

hb_blob_create (const char        *data,

    unsigned int       length,

    hb_memory_mode_t   mode,

    void              *user_data,

    hb_destroy_func_t  destroy)

{

  if (!length)

  {

    if (destroy)

      destroy (user_data);

    return hb_blob_get_empty ();

  }

  hb_blob_t *blob = hb_blob_create_or_fail (data, length, mode,

              user_data, destroy);

  return likely (blob) ? blob : hb_blob_get_empty ();

}

/**

 * hb_blob_create_or_fail: (skip)

 * @data: Pointer to blob data.

 * @length: Length of @data in bytes.

 * @mode: Memory mode for @data.

 * @user_data: Data parameter to pass to @destroy.

 * @destroy: (nullable): Callback to call when @data is not needed anymore.

 *

 * Creates a new "blob" object wrapping @data.  The @mode parameter is used

 * to negotiate ownership and lifecycle of @data.

 *

 * Note that this function returns a freshly-allocated empty blob even if @length

 * is zero. This is in contrast to hb_blob_create(), which returns the singleton

 * empty blob (as returned by hb_blob_get_empty()) if @length is zero.

 *

 * Return value: New blob, or `NULL` if failed.  Destroy with hb_blob_destroy().

 *

 * Since: 2.8.2

 **/

hb_blob_t *

hb_blob_create_or_fail (const char        *data,

      unsigned int       length,

      hb_memory_mode_t   mode,

      void              *user_data,

      hb_destroy_func_t  destroy)

{

  hb_blob_t *blob;

  if (length >= 1u << 31 ||

      !(blob = hb_object_create<hb_blob_t> ()))

  {

    if (destroy)

      destroy (user_data);

    return nullptr;

  }

  blob->data = data;

  blob->length = length;

  blob->mode = mode;

  blob->user_data = user_data;

  blob->destroy = destroy;

  if (blob->mode == HB_MEMORY_MODE_DUPLICATE) {

    blob->mode = HB_MEMORY_MODE_READONLY;

    if (!blob->try_make_writable ())

    {

      hb_blob_destroy (blob);

      return nullptr;

    }

  }

  return blob;

}

static void

_hb_blob_destroy (void *data)

{

  hb_blob_destroy ((hb_blob_t *) data);

}

/**

 * hb_blob_create_sub_blob:

 * @parent: Parent blob.

 * @offset: Start offset of sub-blob within @parent, in bytes.

 * @length: Length of sub-blob.

 *

 * Returns a blob that represents a range of bytes in @parent.  The new

 * blob is always created with #HB_MEMORY_MODE_READONLY, meaning that it

 * will never modify data in the parent blob.  The parent data is not

 * expected to be modified, and will result in undefined behavior if it

 * is.

 *

 * Makes @parent immutable.

 *

 * Return value: New blob, or the empty blob if something failed or if

 * @length is zero or @offset is beyond the end of @parent's data.  Destroy

 * with hb_blob_destroy().

 *

 * Since: 0.9.2

 **/

hb_blob_t *

hb_blob_create_sub_blob (hb_blob_t    *parent,

       unsigned int  offset,

       unsigned int  length)

{

  hb_blob_t *blob;

  if (!length || !parent || offset >= parent->length)

    return hb_blob_get_empty ();

  hb_blob_make_immutable (parent);

  blob = hb_blob_create (parent->data + offset,

       hb_min (length, parent->length - offset),

       HB_MEMORY_MODE_READONLY,

       hb_blob_reference (parent),

       _hb_blob_destroy);

  return blob;

}

/**

 * hb_blob_copy_writable_or_fail:

 * @blob: A blob.

 *

 * Makes a writable copy of @blob.

 *

 * Return value: The new blob, or nullptr if allocation failed

 *

 * Since: 1.8.0

 **/

hb_blob_t *

hb_blob_copy_writable_or_fail (hb_blob_t *blob)

{

  blob = hb_blob_create (blob->data,

       blob->length,

       HB_MEMORY_MODE_DUPLICATE,

       nullptr,

       nullptr);

  if (unlikely (blob == hb_blob_get_empty ()))

    blob = nullptr;

  return blob;

}

/**

 * hb_blob_get_empty:

 *

 * Returns the singleton empty blob.

 *

 * See TODO:link object types for more information.

 *

 * Return value: (transfer full): The empty blob.

 *

 * Since: 0.9.2

 **/

hb_blob_t *

hb_blob_get_empty ()

{

  return const_cast<hb_blob_t *> (&Null (hb_blob_t));

}

/**

 * hb_blob_reference: (skip)

 * @blob: a blob.

 *

 * Increases the reference count on @blob.

 *

 * See TODO:link object types for more information.

 *

 * Return value: @blob.

 *

 * Since: 0.9.2

 **/

hb_blob_t *

hb_blob_reference (hb_blob_t *blob)

{

  return hb_object_reference (blob);

}

/**

 * hb_blob_destroy: (skip)

 * @blob: a blob.

 *

 * Decreases the reference count on @blob, and if it reaches zero, destroys

 * @blob, freeing all memory, possibly calling the destroy-callback the blob

 * was created for if it has not been called already.

 *

 * See TODO:link object types for more information.

 *

 * Since: 0.9.2

 **/

void

hb_blob_destroy (hb_blob_t *blob)

{

  if (!hb_object_destroy (blob)) return;

  hb_free (blob);

}

/**

 * hb_blob_set_user_data: (skip)

 * @blob: An #hb_blob_t

 * @key: The user-data key to set

 * @data: A pointer to the user data to set

 * @destroy: (nullable): A callback to call when @data is not needed anymore

 * @replace: Whether to replace an existing data with the same key

 *

 * Attaches a user-data key/data pair to the specified blob.

 *

 * Return value: `true` if success, `false` otherwise

 *

 * Since: 0.9.2

 **/

hb_bool_t

hb_blob_set_user_data (hb_blob_t          *blob,

           hb_user_data_key_t *key,

           void *              data,

           hb_destroy_func_t   destroy,

           hb_bool_t           replace)

{

  return hb_object_set_user_data (blob, key, data, destroy, replace);

}

/**

 * hb_blob_get_user_data: (skip)

 * @blob: a blob

 * @key: The user-data key to query

 *

 * Fetches the user data associated with the specified key,

 * attached to the specified font-functions structure.

 *

 * Return value: (transfer none): A pointer to the user data

 *

 * Since: 0.9.2

 **/

void *

hb_blob_get_user_data (const hb_blob_t    *blob,

           hb_user_data_key_t *key)

{

  return hb_object_get_user_data (blob, key);

}

/**

 * hb_blob_make_immutable:

 * @blob: a blob

 *

 * Makes a blob immutable.

 *

 * Since: 0.9.2

 **/

void

hb_blob_make_immutable (hb_blob_t *blob)

{

  if (hb_object_is_immutable (blob))

    return;

  hb_object_make_immutable (blob);

}

/**

 * hb_blob_is_immutable:

 * @blob: a blob.

 *

 * Tests whether a blob is immutable.

 *

 * Return value: `true` if @blob is immutable, `false` otherwise

 *

 * Since: 0.9.2

 **/

hb_bool_t

hb_blob_is_immutable (hb_blob_t *blob)

{

  return hb_object_is_immutable (blob);

}

/**

 * hb_blob_get_length:

 * @blob: a blob.

 *

 * Fetches the length of a blob's data.

 *

 * Return value: the length of @blob data in bytes.

 *

 * Since: 0.9.2

 **/

unsigned int

hb_blob_get_length (hb_blob_t *blob)

{

  return blob->length;

}

/**

 * hb_blob_get_data:

 * @blob: a blob.

 * @length: (out): The length in bytes of the data retrieved

 *

 * Fetches the data from a blob.

 *

 * Returns: (nullable) (transfer none) (array length=length): the byte data of @blob.

 *

 * Since: 0.9.2

 **/

const char *

hb_blob_get_data (hb_blob_t *blob, unsigned int *length)

{

  if (length)

    *length = blob->length;

  return blob->data;

}

/**

 * hb_blob_get_data_writable:

 * @blob: a blob.

 * @length: (out): output length of the writable data.

 *

 * Tries to make blob data writable (possibly copying it) and

 * return pointer to data.

 *

 * Fails if blob has been made immutable, or if memory allocation

 * fails.

 *

 * Returns: (transfer none) (array length=length): Writable blob data,

 * or `NULL` if failed.

 *

 * Since: 0.9.2

 **/

char *

hb_blob_get_data_writable (hb_blob_t *blob, unsigned int *length)

{

  if (hb_object_is_immutable (blob) ||

     !blob->try_make_writable ())

  {

    if (length) *length = 0;

    return nullptr;

  }

  if (length) *length = blob->length;

  return const_cast<char *> (blob->data);

}

bool

hb_blob_t::try_make_writable_inplace_unix ()

{

#if defined(HAVE_SYS_MMAN_H) && defined(HAVE_MPROTECT)

  uintptr_t pagesize = -1, mask, length;

  const char *addr;

#if defined(HAVE_SYSCONF) && defined(_SC_PAGE_SIZE)

  pagesize = (uintptr_t) sysconf (_SC_PAGE_SIZE);

#elif defined(HAVE_SYSCONF) && defined(_SC_PAGESIZE)

  pagesize = (uintptr_t) sysconf (_SC_PAGESIZE);

#elif defined(HAVE_GETPAGESIZE)

  pagesize = (uintptr_t) getpagesize ();

#endif

  if ((uintptr_t) -1L == pagesize) {

    DEBUG_MSG_FUNC (BLOB, this, "failed to get pagesize: %s", strerror (errno));

    return false;

  }

  DEBUG_MSG_FUNC (BLOB, this, "pagesize is %lu", (unsigned long) pagesize);

  mask = ~(pagesize-1);

  addr = (const char *) (((uintptr_t) this->data) & mask);

  length = (const char *) (((uintptr_t) this->data + this->length + pagesize-1) & mask)  - addr;

  DEBUG_MSG_FUNC (BLOB, this,

      "calling mprotect on [%p..%p] (%lu bytes)",

      addr, addr+length, (unsigned long) length);

  if (-1 == mprotect ((void *) addr, length, PROT_READ | PROT_WRITE)) {

    DEBUG_MSG_FUNC (BLOB, this, "mprotect failed: %s", strerror (errno));

    return false;

  }

  this->mode = HB_MEMORY_MODE_WRITABLE;

  DEBUG_MSG_FUNC (BLOB, this,

      "successfully made [%p..%p] (%lu bytes) writable\n",

      addr, addr+length, (unsigned long) length);

  return true;

#else

  return false;

#endif

}

bool

hb_blob_t::try_make_writable_inplace ()

{

  DEBUG_MSG_FUNC (BLOB, this, "making writable inplace\n");

  if (this->try_make_writable_inplace_unix ())

    return true;

  DEBUG_MSG_FUNC (BLOB, this, "making writable -> FAILED\n");

  /* Failed to make writable inplace, mark that */

  this->mode = HB_MEMORY_MODE_READONLY;

  return false;

}

bool

hb_blob_t::try_make_writable ()

{

  if (unlikely (!length))

    mode = HB_MEMORY_MODE_WRITABLE;

  if (this->mode == HB_MEMORY_MODE_WRITABLE)

    return true;

  if (this->mode == HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE && this->try_make_writable_inplace ())

    return true;

  if (this->mode == HB_MEMORY_MODE_WRITABLE)

    return true;

  DEBUG_MSG_FUNC (BLOB, this, "current data is -> %p\n", this->data);

  char *new_data;

  new_data = (char *) hb_malloc (this->length);

  if (unlikely (!new_data))

    return false;

  DEBUG_MSG_FUNC (BLOB, this, "dupped successfully -> %p\n", this->data);

  hb_memcpy (new_data, this->data, this->length);

  this->destroy_user_data ();

  this->mode = HB_MEMORY_MODE_WRITABLE;

  this->data = new_data;

  this->user_data = new_data;

  this->destroy = hb_free;

  return true;

}

/*

 * Mmap

 */

#ifndef HB_NO_OPEN

#ifdef HAVE_MMAP

# if !defined(HB_NO_RESOURCE_FORK) && defined(__APPLE__)

#  include <sys/paths.h>

# endif

# include <sys/types.h>

# include <sys/stat.h>

# include <fcntl.h>

#endif

#ifdef _WIN32

# include <windows.h>

#else

# ifndef O_BINARY

#  define O_BINARY 0

# endif

#endif

#ifndef MAP_NORESERVE

# define MAP_NORESERVE 0

#endif

struct hb_mapped_file_t

{

  char *contents;

  unsigned long length;

#ifdef _WIN32

  HANDLE mapping;

#endif

};

#if (defined(HAVE_MMAP) || defined(_WIN32)) && !defined(HB_NO_MMAP)

static void

_hb_mapped_file_destroy (void *file_)

{

  hb_mapped_file_t *file = (hb_mapped_file_t *) file_;

#ifdef HAVE_MMAP

  munmap (file->contents, file->length);

#elif defined(_WIN32)

  UnmapViewOfFile (file->contents);

  CloseHandle (file->mapping);

#else

  assert (0); // If we don't have mmap we shouldn't reach here

#endif

  hb_free (file);

}

#endif

#ifdef _PATH_RSRCFORKSPEC

static int

_open_resource_fork (const char *file_name, hb_mapped_file_t *file)

{

  size_t name_len = strlen (file_name);

  size_t len = name_len + sizeof (_PATH_RSRCFORKSPEC);

  char *rsrc_name = (char *) hb_malloc (len);

  if (unlikely (!rsrc_name)) return -1;

  strncpy (rsrc_name, file_name, name_len);

  strncpy (rsrc_name + name_len, _PATH_RSRCFORKSPEC,

     sizeof (_PATH_RSRCFORKSPEC));

  int fd = open (rsrc_name, O_RDONLY | O_BINARY, 0);

  hb_free (rsrc_name);

  if (fd != -1)

  {

    struct stat st;

    if (fstat (fd, &st) != -1)

      file->length = (unsigned long) st.st_size;

    else

    {

      close (fd);

      fd = -1;

    }

  }

  return fd;

}

#endif

/**

 * hb_blob_create_from_file:

 * @file_name: A font filename

 *

 * Creates a new blob containing the data from the

 * specified binary font file.

 *

 * Returns: An #hb_blob_t pointer with the content of the file,

 * or hb_blob_get_empty() if failed.

 *

 * Since: 1.7.7

 **/

hb_blob_t *

hb_blob_create_from_file (const char *file_name)

{

  hb_blob_t *blob = hb_blob_create_from_file_or_fail (file_name);

  return likely (blob) ? blob : hb_blob_get_empty ();

}

/**

 * hb_blob_create_from_file_or_fail:

 * @file_name: A font filename

 *

 * Creates a new blob containing the data from the

 * specified binary font file.

 *

 * Returns: An #hb_blob_t pointer with the content of the file,

 * or `NULL` if failed.

 *

 * Since: 2.8.2

 **/

hb_blob_t *

hb_blob_create_from_file_or_fail (const char *file_name)

{

  /* Adopted from glib's gmappedfile.c with Matthias Clasen and

     Allison Lortie permission but changed a lot to suit our need. */

#if defined(HAVE_MMAP) && !defined(HB_NO_MMAP)

  hb_mapped_file_t *file = (hb_mapped_file_t *) hb_calloc (1, sizeof (hb_mapped_file_t));

  if (unlikely (!file)) return nullptr;

  int fd = open (file_name, O_RDONLY | O_BINARY, 0);

  if (unlikely (fd == -1)) goto fail_without_close;

  struct stat st;

  if (unlikely (fstat (fd, &st) == -1)) goto fail;

  file->length = (unsigned long) st.st_size;

#ifdef _PATH_RSRCFORKSPEC

  if (unlikely (file->length == 0))

  {

    int rfd = _open_resource_fork (file_name, file);

    if (rfd != -1)

    {

      close (fd);

      fd = rfd;

    }

  }

#endif

  file->contents = (char *) mmap (nullptr, file->length, PROT_READ,

          MAP_PRIVATE | MAP_NORESERVE, fd, 0);

  if (unlikely (file->contents == MAP_FAILED)) goto fail;

  close (fd);

  return hb_blob_create_or_fail (file->contents, file->length,

         HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE, (void *) file,

         (hb_destroy_func_t) _hb_mapped_file_destroy);

fail:

  close (fd);

fail_without_close:

  hb_free (file);

#elif defined(_WIN32) && !defined(HB_NO_MMAP)

  hb_mapped_file_t *file = (hb_mapped_file_t *) hb_calloc (1, sizeof (hb_mapped_file_t));

  if (unlikely (!file)) return nullptr;

  HANDLE fd;

  unsigned int size = strlen (file_name) + 1;

  wchar_t * wchar_file_name = (wchar_t *) hb_malloc (sizeof (wchar_t) * size);

  if (unlikely (!wchar_file_name)) goto fail_without_close;

  mbstowcs (wchar_file_name, file_name, size);

#if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) && WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)

  {

    CREATEFILE2_EXTENDED_PARAMETERS ceparams = { 0 };

    ceparams.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);

    ceparams.dwFileAttributes = FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED & 0xFFFF;

    ceparams.dwFileFlags = FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED & 0xFFF00000;

    ceparams.dwSecurityQosFlags = FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED & 0x000F0000;

    ceparams.lpSecurityAttributes = nullptr;

    ceparams.hTemplateFile = nullptr;

    fd = CreateFile2 (wchar_file_name, GENERIC_READ, FILE_SHARE_READ,

          OPEN_EXISTING, &ceparams);

  }

#else

  fd = CreateFileW (wchar_file_name, GENERIC_READ, FILE_SHARE_READ, nullptr,

        OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED,

        nullptr);

#endif

  hb_free (wchar_file_name);

  if (unlikely (fd == INVALID_HANDLE_VALUE)) goto fail_without_close;

#if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) && WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)

  {

    LARGE_INTEGER length;

    GetFileSizeEx (fd, &length);

    file->length = length.LowPart;

    file->mapping = CreateFileMappingFromApp (fd, nullptr, PAGE_READONLY, length.QuadPart, nullptr);

  }

#else

  file->length = (unsigned long) GetFileSize (fd, nullptr);

  file->mapping = CreateFileMapping (fd, nullptr, PAGE_READONLY, 0, 0, nullptr);

#endif

  if (unlikely (!file->mapping)) goto fail;

#if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) && WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)

  file->contents = (char *) MapViewOfFileFromApp (file->mapping, FILE_MAP_READ, 0, 0);

#else

  file->contents = (char *) MapViewOfFile (file->mapping, FILE_MAP_READ, 0, 0, 0);

#endif

  if (unlikely (!file->contents)) goto fail;

  CloseHandle (fd);

  return hb_blob_create_or_fail (file->contents, file->length,

         HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE, (void *) file,

         (hb_destroy_func_t) _hb_mapped_file_destroy);

fail:

  CloseHandle (fd);

fail_without_close:

  hb_free (file);

#endif

  /* The following tries to read a file without knowing its size beforehand

     It's used as a fallback for systems without mmap or to read from pipes */

  unsigned long len = 0, allocated = BUFSIZ * 16;

  char *data = (char *) hb_malloc (allocated);

  if (unlikely (!data)) return nullptr;

  FILE *fp = fopen (file_name, "rb");

  if (unlikely (!fp)) goto fread_fail_without_close;

  while (!feof (fp))

  {

    if (allocated - len < BUFSIZ)

    {

      allocated *= 2;

      /* Don't allocate and go more than ~536MB, our mmap reader still

   can cover files like that but lets limit our fallback reader */

      if (unlikely (allocated > (2 << 28))) goto fread_fail;

      char *new_data = (char *) hb_realloc (data, allocated);

      if (unlikely (!new_data)) goto fread_fail;

      data = new_data;

    }

    unsigned long addition = fread (data + len, 1, allocated - len, fp);

    int err = ferror (fp);

#ifdef EINTR // armcc doesn't have it

    if (unlikely (err == EINTR)) continue;

#endif

    if (unlikely (err)) goto fread_fail;

    len += addition;

  }

  fclose (fp);

  return hb_blob_create_or_fail (data, len, HB_MEMORY_MODE_WRITABLE, data,

         (hb_destroy_func_t) hb_free);

fread_fail:

  fclose (fp);

fread_fail_without_close:

  hb_free (data);

  return nullptr;

}

#endif /* !HB_NO_OPEN */