/* * Copyright © 2009 Red Hat, Inc. * * 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 */ /* http://www.oracle.com/technetwork/articles/servers-storage-dev/standardheaderfiles-453865.html */ #define _POSIX_C_SOURCE 199309L #include "hb-private.hh" #include "hb-object-private.hh" #ifdef HAVE_SYS_MMAN_H #ifdef HAVE_UNISTD_H #include #endif /* HAVE_UNISTD_H */ #include #endif /* HAVE_SYS_MMAN_H */ #include #include #ifndef HB_DEBUG_BLOB #define HB_DEBUG_BLOB (HB_DEBUG+0) #endif struct hb_blob_t { hb_object_header_t header; ASSERT_POD (); bool immutable; const char *data; unsigned int length; hb_memory_mode_t mode; void *user_data; hb_destroy_func_t destroy; }; static bool _try_writable (hb_blob_t *blob); static void _hb_blob_destroy_user_data (hb_blob_t *blob) { if (blob->destroy) { blob->destroy (blob->user_data); blob->user_data = NULL; blob->destroy = NULL; } } /** * hb_blob_create: (Xconstructor) * @data: (array length=length) (closure user_data) (destroy destroy) (scope notified) (transfer none): Pointer to blob data. * @length: Length of @data in bytes. * @mode: Memory mode for @data. * @user_data: Data parameter to pass to @destroy. * @destroy: 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: 1.0 **/ 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) { hb_blob_t *blob; if (!length || !(blob = hb_object_create ())) { if (destroy) destroy (user_data); return hb_blob_get_empty (); } 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 (!_try_writable (blob)) { hb_blob_destroy (blob); return hb_blob_get_empty (); } } return blob; } /** * 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: 1.0 **/ hb_blob_t * hb_blob_create_sub_blob (hb_blob_t *parent, unsigned int offset, unsigned int length) { hb_blob_t *blob; if (!length || offset >= parent->length) return hb_blob_get_empty (); hb_blob_make_immutable (parent); blob = hb_blob_create (parent->data + offset, MIN (length, parent->length - offset), HB_MEMORY_MODE_READONLY, hb_blob_reference (parent), (hb_destroy_func_t) hb_blob_destroy); 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: 1.0 **/ hb_blob_t * hb_blob_get_empty (void) { static const hb_blob_t _hb_blob_nil = { HB_OBJECT_HEADER_STATIC, true, /* immutable */ NULL, /* data */ 0, /* length */ HB_MEMORY_MODE_READONLY, /* mode */ NULL, /* user_data */ NULL /* destroy */ }; return const_cast (&_hb_blob_nil); } /** * 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: 1.0 **/ hb_blob_t * hb_blob_reference (hb_blob_t *blob) { return hb_object_reference (blob); } /** * hb_blob_destroy: (skip) * @blob: a blob. * * Descreases 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: 1.0 **/ void hb_blob_destroy (hb_blob_t *blob) { if (!hb_object_destroy (blob)) return; _hb_blob_destroy_user_data (blob); free (blob); } /** * hb_blob_set_user_data: (skip) * @blob: a blob. * @key: key for data to set. * @data: data to set. * @destroy: callback to call when @data is not needed anymore. * @replace: whether to replace an existing data with the same key. * * Return value: * * Since: 1.0 **/ 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: key for data to get. * * * * Return value: (transfer none): * * Since: 1.0 **/ void * hb_blob_get_user_data (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. * * * * Since: 1.0 **/ void hb_blob_make_immutable (hb_blob_t *blob) { if (hb_object_is_inert (blob)) return; blob->immutable = true; } /** * hb_blob_is_immutable: * @blob: a blob. * * * * Return value: TODO * * Since: 1.0 **/ hb_bool_t hb_blob_is_immutable (hb_blob_t *blob) { return blob->immutable; } /** * hb_blob_get_length: * @blob: a blob. * * * * Return value: the length of blob data in bytes. * * Since: 1.0 **/ unsigned int hb_blob_get_length (hb_blob_t *blob) { return blob->length; } /** * hb_blob_get_data: * @blob: a blob. * @length: (out): * * * * Returns: (transfer none) (array length=length): * * Since: 1.0 **/ 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: 1.0 **/ char * hb_blob_get_data_writable (hb_blob_t *blob, unsigned int *length) { if (!_try_writable (blob)) { if (length) *length = 0; return NULL; } if (length) *length = blob->length; return const_cast (blob->data); } static hb_bool_t _try_make_writable_inplace_unix (hb_blob_t *blob) { #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, blob, "failed to get pagesize: %s", strerror (errno)); return false; } DEBUG_MSG_FUNC (BLOB, blob, "pagesize is %lu", (unsigned long) pagesize); mask = ~(pagesize-1); addr = (const char *) (((uintptr_t) blob->data) & mask); length = (const char *) (((uintptr_t) blob->data + blob->length + pagesize-1) & mask) - addr; DEBUG_MSG_FUNC (BLOB, blob, "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, blob, "mprotect failed: %s", strerror (errno)); return false; } blob->mode = HB_MEMORY_MODE_WRITABLE; DEBUG_MSG_FUNC (BLOB, blob, "successfully made [%p..%p] (%lu bytes) writable\n", addr, addr+length, (unsigned long) length); return true; #else return false; #endif } static bool _try_writable_inplace (hb_blob_t *blob) { DEBUG_MSG_FUNC (BLOB, blob, "making writable inplace\n"); if (_try_make_writable_inplace_unix (blob)) return true; DEBUG_MSG_FUNC (BLOB, blob, "making writable -> FAILED\n"); /* Failed to make writable inplace, mark that */ blob->mode = HB_MEMORY_MODE_READONLY; return false; } static bool _try_writable (hb_blob_t *blob) { if (blob->immutable) return false; if (blob->mode == HB_MEMORY_MODE_WRITABLE) return true; if (blob->mode == HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE && _try_writable_inplace (blob)) return true; if (blob->mode == HB_MEMORY_MODE_WRITABLE) return true; DEBUG_MSG_FUNC (BLOB, blob, "current data is -> %p\n", blob->data); char *new_data; new_data = (char *) malloc (blob->length); if (unlikely (!new_data)) return false; DEBUG_MSG_FUNC (BLOB, blob, "dupped successfully -> %p\n", blob->data); memcpy (new_data, blob->data, blob->length); _hb_blob_destroy_user_data (blob); blob->mode = HB_MEMORY_MODE_WRITABLE; blob->data = new_data; blob->user_data = new_data; blob->destroy = free; return true; }