/* GStreamer

 * Copyright (C) 2011 Wim Taymans <wim.taymans@gmail.be>

 *

 * gstallocator.c: memory block allocator

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

/**

 * SECTION:gstallocator

 * @title: GstAllocator

 * @short_description: allocate memory blocks

 * @see_also: #GstMemory

 *

 * Memory is usually created by allocators with a gst_allocator_alloc()

 * method call. When %NULL is used as the allocator, the default allocator will

 * be used.

 *

 * New allocators can be registered with gst_allocator_register().

 * Allocators are identified by name and can be retrieved with

 * gst_allocator_find(). gst_allocator_set_default() can be used to change the

 * default allocator.

 *

 * New memory can be created with gst_memory_new_wrapped() that wraps the memory

 * allocated elsewhere.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "gst_private.h"

#include "gstmemory.h"

GST_DEBUG_CATEGORY_STATIC (gst_allocator_debug);

#define GST_CAT_DEFAULT gst_allocator_debug

#define GST_ALLOCATOR_GET_PRIVATE(obj)  \

     (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_ALLOCATOR, GstAllocatorPrivate))

struct _GstAllocatorPrivate

{

  gpointer dummy;

};

#if defined(MEMORY_ALIGNMENT_MALLOC)

gsize gst_memory_alignment = 7;

#elif defined(MEMORY_ALIGNMENT_PAGESIZE)

/* we fill this in in the _init method */

gsize gst_memory_alignment = 0;

#elif defined(MEMORY_ALIGNMENT)

gsize gst_memory_alignment = MEMORY_ALIGNMENT - 1;

#else

#error "No memory alignment configured"

gsize gst_memory_alignment = 0;

#endif

/* the default allocator */

static GstAllocator *_default_allocator;

static GstAllocator *_sysmem_allocator;

/* registered allocators */

static GRWLock lock;

static GHashTable *allocators;

G_DEFINE_ABSTRACT_TYPE (GstAllocator, gst_allocator, GST_TYPE_OBJECT);

static void

gst_allocator_class_init (GstAllocatorClass * klass)

{

  g_type_class_add_private (klass, sizeof (GstAllocatorPrivate));

  GST_DEBUG_CATEGORY_INIT (gst_allocator_debug, "allocator", 0,

      "allocator debug");

}

static GstMemory *

_fallback_mem_copy (GstMemory * mem, gssize offset, gssize size)

{

  GstMemory *copy;

  GstMapInfo sinfo, dinfo;

  GstAllocationParams params = { 0, mem->align, 0, 0, };

  GstAllocator *allocator;

  if (!gst_memory_map (mem, &sinfo, GST_MAP_READ))

    return NULL;

  if (size == -1)

    size = sinfo.size > offset ? sinfo.size - offset : 0;

  /* use the same allocator as the memory we copy  */

  allocator = mem->allocator;

  if (GST_OBJECT_FLAG_IS_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC))

    allocator = NULL;

  copy = gst_allocator_alloc (allocator, size, &params);

  if (!gst_memory_map (copy, &dinfo, GST_MAP_WRITE)) {

    GST_CAT_WARNING (GST_CAT_MEMORY, "could not write map memory %p", copy);

    gst_allocator_free (mem->allocator, copy);

    gst_memory_unmap (mem, &sinfo);

    return NULL;

  }

  GST_CAT_DEBUG (GST_CAT_PERFORMANCE,

      "memcpy %" G_GSSIZE_FORMAT " memory %p -> %p", size, mem, copy);

  memcpy (dinfo.data, sinfo.data + offset, size);

  gst_memory_unmap (copy, &dinfo);

  gst_memory_unmap (mem, &sinfo);

  return copy;

}

static gboolean

_fallback_mem_is_span (GstMemory * mem1, GstMemory * mem2, gsize * offset)

{

  return FALSE;

}

static void

gst_allocator_init (GstAllocator * allocator)

{

  allocator->priv = GST_ALLOCATOR_GET_PRIVATE (allocator);

  allocator->mem_copy = _fallback_mem_copy;

  allocator->mem_is_span = _fallback_mem_is_span;

}

G_DEFINE_BOXED_TYPE (GstAllocationParams, gst_allocation_params,

    (GBoxedCopyFunc) gst_allocation_params_copy,

    (GBoxedFreeFunc) gst_allocation_params_free);

/**

 * gst_allocation_params_init:

 * @params: a #GstAllocationParams

 *

 * Initialize @params to its default values

 */

void

gst_allocation_params_init (GstAllocationParams * params)

{

  g_return_if_fail (params != NULL);

  memset (params, 0, sizeof (GstAllocationParams));

}

/**

 * gst_allocation_params_copy:

 * @params: (transfer none) (nullable): a #GstAllocationParams

 *

 * Create a copy of @params.

 *

 * Free-function: gst_allocation_params_free

 *

 * Returns: (transfer full) (nullable): a new ##GstAllocationParams, free with

 * gst_allocation_params_free().

 */

GstAllocationParams *

gst_allocation_params_copy (const GstAllocationParams * params)

{

  GstAllocationParams *result = NULL;

  if (params) {

    result =

        (GstAllocationParams *) g_slice_copy (sizeof (GstAllocationParams),

        params);

  }

  return result;

}

/**

 * gst_allocation_params_free:

 * @params: (in) (transfer full): a #GstAllocationParams

 *

 * Free @params

 */

void

gst_allocation_params_free (GstAllocationParams * params)

{

  g_slice_free (GstAllocationParams, params);

}

/**

 * gst_allocator_register:

 * @name: the name of the allocator

 * @allocator: (transfer full): #GstAllocator

 *

 * Registers the memory @allocator with @name. This function takes ownership of

 * @allocator.

 */

void

gst_allocator_register (const gchar * name, GstAllocator * allocator)

{

  g_return_if_fail (name != NULL);

  g_return_if_fail (allocator != NULL);

  GST_CAT_DEBUG (GST_CAT_MEMORY, "registering allocator %p with name \"%s\"",

      allocator, name);

  g_rw_lock_writer_lock (&lock);

  /* The ref will never be released */

  GST_OBJECT_FLAG_SET (allocator, GST_OBJECT_FLAG_MAY_BE_LEAKED);

  g_hash_table_insert (allocators, (gpointer) name, (gpointer) allocator);

  g_rw_lock_writer_unlock (&lock);

}

/**

 * gst_allocator_find:

 * @name: (allow-none): the name of the allocator

 *

 * Find a previously registered allocator with @name. When @name is %NULL, the

 * default allocator will be returned.

 *

 * Returns: (transfer full) (nullable): a #GstAllocator or %NULL when

 * the allocator with @name was not registered. Use gst_object_unref()

 * to release the allocator after usage.

 */

GstAllocator *

gst_allocator_find (const gchar * name)

{

  GstAllocator *allocator;

  g_rw_lock_reader_lock (&lock);

  if (name) {

    allocator = g_hash_table_lookup (allocators, (gconstpointer) name);

  } else {

    allocator = _default_allocator;

  }

  if (allocator)

    gst_object_ref (allocator);

  g_rw_lock_reader_unlock (&lock);

  return allocator;

}

/**

 * gst_allocator_set_default:

 * @allocator: (transfer full): a #GstAllocator

 *

 * Set the default allocator. This function takes ownership of @allocator.

 */

void

gst_allocator_set_default (GstAllocator * allocator)

{

  GstAllocator *old;

  g_return_if_fail (GST_IS_ALLOCATOR (allocator));

  g_rw_lock_writer_lock (&lock);

  old = _default_allocator;

  _default_allocator = allocator;

  g_rw_lock_writer_unlock (&lock);

  if (old)

    gst_object_unref (old);

}

/**

 * gst_allocator_alloc:

 * @allocator: (transfer none) (allow-none): a #GstAllocator to use

 * @size: size of the visible memory area

 * @params: (transfer none) (allow-none): optional parameters

 *

 * Use @allocator to allocate a new memory block with memory that is at least

 * @size big.

 *

 * The optional @params can specify the prefix and padding for the memory. If

 * %NULL is passed, no flags, no extra prefix/padding and a default alignment is

 * used.

 *

 * The prefix/padding will be filled with 0 if flags contains

 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.

 *

 * When @allocator is %NULL, the default allocator will be used.

 *

 * The alignment in @params is given as a bitmask so that @align + 1 equals

 * the amount of bytes to align to. For example, to align to 8 bytes,

 * use an alignment of 7.

 *

 * Returns: (transfer full) (nullable): a new #GstMemory.

 */

GstMemory *

gst_allocator_alloc (GstAllocator * allocator, gsize size,

    GstAllocationParams * params)

{

  GstMemory *mem;

  static GstAllocationParams defparams = { 0, 0, 0, 0, };

  GstAllocatorClass *aclass;

  if (params) {

    g_return_val_if_fail (((params->align + 1) & params->align) == 0, NULL);

  } else {

    params = &defparams;

  }

  if (allocator == NULL)

    allocator = _default_allocator;

  aclass = GST_ALLOCATOR_GET_CLASS (allocator);

  if (aclass->alloc)

    mem = aclass->alloc (allocator, size, params);

  else

    mem = NULL;

  return mem;

}

/**

 * gst_allocator_free:

 * @allocator: (transfer none): a #GstAllocator to use

 * @memory: (transfer full): the memory to free

 *

 * Free @memory that was previously allocated with gst_allocator_alloc().

 */

void

gst_allocator_free (GstAllocator * allocator, GstMemory * memory)

{

  GstAllocatorClass *aclass;

  g_return_if_fail (GST_IS_ALLOCATOR (allocator));

  g_return_if_fail (memory != NULL);

  g_return_if_fail (memory->allocator == allocator);

  aclass = GST_ALLOCATOR_GET_CLASS (allocator);

  if (aclass->free)

    aclass->free (allocator, memory);

}

/* default memory implementation */

typedef struct

{

  GstMemory mem;

  gsize slice_size;

  guint8 *data;

  gpointer user_data;

  GDestroyNotify notify;

} GstMemorySystem;

typedef struct

{

  GstAllocator parent;

} GstAllocatorSysmem;

typedef struct

{

  GstAllocatorClass parent_class;

} GstAllocatorSysmemClass;

static GType gst_allocator_sysmem_get_type (void);

G_DEFINE_TYPE (GstAllocatorSysmem, gst_allocator_sysmem, GST_TYPE_ALLOCATOR);

/* initialize the fields */

static inline void

_sysmem_init (GstMemorySystem * mem, GstMemoryFlags flags,

    GstMemory * parent, gsize slice_size,

    gpointer data, gsize maxsize, gsize align, gsize offset, gsize size,

    gpointer user_data, GDestroyNotify notify)

{

  gst_memory_init (GST_MEMORY_CAST (mem),

      flags, _sysmem_allocator, parent, maxsize, align, offset, size);

  mem->slice_size = slice_size;

  mem->data = data;

  mem->user_data = user_data;

  mem->notify = notify;

}

/* create a new memory block that manages the given memory */

static inline GstMemorySystem *

_sysmem_new (GstMemoryFlags flags,

    GstMemory * parent, gpointer data, gsize maxsize, gsize align, gsize offset,

    gsize size, gpointer user_data, GDestroyNotify notify)

{

  GstMemorySystem *mem;

  gsize slice_size;

  slice_size = sizeof (GstMemorySystem);

  mem = g_slice_alloc (slice_size);

  _sysmem_init (mem, flags, parent, slice_size,

      data, maxsize, align, offset, size, user_data, notify);

  return mem;

}

/* allocate the memory and structure in one block */

static GstMemorySystem *

_sysmem_new_block (GstMemoryFlags flags,

    gsize maxsize, gsize align, gsize offset, gsize size)

{

  GstMemorySystem *mem;

  gsize aoffset, slice_size, padding;

  guint8 *data;

  /* ensure configured alignment */

  align |= gst_memory_alignment;

  /* allocate more to compensate for alignment */

  maxsize += align;

  /* alloc header and data in one block */

  slice_size = sizeof (GstMemorySystem) + maxsize;

  mem = g_slice_alloc (slice_size);

  if (mem == NULL)

    return NULL;

  data = (guint8 *) mem + sizeof (GstMemorySystem);

  /* do alignment */

  if ((aoffset = ((guintptr) data & align))) {

    aoffset = (align + 1) - aoffset;

    data += aoffset;

    maxsize -= aoffset;

  }

  if (offset && (flags & GST_MEMORY_FLAG_ZERO_PREFIXED))

    memset (data, 0, offset);

  padding = maxsize - (offset + size);

  if (padding && (flags & GST_MEMORY_FLAG_ZERO_PADDED))

    memset (data + offset + size, 0, padding);

  _sysmem_init (mem, flags, NULL, slice_size, data, maxsize,

      align, offset, size, NULL, NULL);

  return mem;

}

static gpointer

_sysmem_map (GstMemorySystem * mem, gsize maxsize, GstMapFlags flags)

{

  return mem->data;

}

static gboolean

_sysmem_unmap (GstMemorySystem * mem)

{

  return TRUE;

}

static GstMemorySystem *

_sysmem_copy (GstMemorySystem * mem, gssize offset, gsize size)

{

  GstMemorySystem *copy;

  if (size == -1)

    size = mem->mem.size > offset ? mem->mem.size - offset : 0;

  copy = _sysmem_new_block (0, size, mem->mem.align, 0, size);

  GST_CAT_DEBUG (GST_CAT_PERFORMANCE,

      "memcpy %" G_GSIZE_FORMAT " memory %p -> %p", size, mem, copy);

  memcpy (copy->data, mem->data + mem->mem.offset + offset, size);

  return copy;

}

static GstMemorySystem *

_sysmem_share (GstMemorySystem * mem, gssize offset, gsize size)

{

  GstMemorySystem *sub;

  GstMemory *parent;

  /* find the real parent */

  if ((parent = mem->mem.parent) == NULL)

    parent = (GstMemory *) mem;

  if (size == -1)

    size = mem->mem.size - offset;

  /* the shared memory is always readonly */

  sub =

      _sysmem_new (GST_MINI_OBJECT_FLAGS (parent) |

      GST_MINI_OBJECT_FLAG_LOCK_READONLY, parent, mem->data, mem->mem.maxsize,

      mem->mem.align, mem->mem.offset + offset, size, NULL, NULL);

  return sub;

}

static gboolean

_sysmem_is_span (GstMemorySystem * mem1, GstMemorySystem * mem2, gsize * offset)

{

  if (offset) {

    GstMemorySystem *parent;

    parent = (GstMemorySystem *) mem1->mem.parent;

    *offset = mem1->mem.offset - parent->mem.offset;

  }

  /* and memory is contiguous */

  return mem1->data + mem1->mem.offset + mem1->mem.size ==

      mem2->data + mem2->mem.offset;

}

static GstMemory *

default_alloc (GstAllocator * allocator, gsize size,

    GstAllocationParams * params)

{

  gsize maxsize = size + params->prefix + params->padding;

  return (GstMemory *) _sysmem_new_block (params->flags,

      maxsize, params->align, params->prefix, size);

}

static void

default_free (GstAllocator * allocator, GstMemory * mem)

{

  GstMemorySystem *dmem = (GstMemorySystem *) mem;

  gsize slice_size;

  if (dmem->notify)

    dmem->notify (dmem->user_data);

  slice_size = dmem->slice_size;

#ifdef USE_POISONING

  /* just poison the structs, not all the data */

  memset (mem, 0xff, sizeof (GstMemorySystem));

#endif

  g_slice_free1 (slice_size, mem);

}

static void

gst_allocator_sysmem_finalize (GObject * obj)

{

  /* Don't raise warnings if we are shutting down */

  if (_default_allocator)

    g_warning ("The default memory allocator was freed!");

  ((GObjectClass *) gst_allocator_sysmem_parent_class)->finalize (obj);

}

static void

gst_allocator_sysmem_class_init (GstAllocatorSysmemClass * klass)

{

  GObjectClass *gobject_class;

  GstAllocatorClass *allocator_class;

  gobject_class = (GObjectClass *) klass;

  allocator_class = (GstAllocatorClass *) klass;

  gobject_class->finalize = gst_allocator_sysmem_finalize;

  allocator_class->alloc = default_alloc;

  allocator_class->free = default_free;

}

static void

gst_allocator_sysmem_init (GstAllocatorSysmem * allocator)

{

  GstAllocator *alloc = GST_ALLOCATOR_CAST (allocator);

  GST_CAT_DEBUG (GST_CAT_MEMORY, "init allocator %p", allocator);

  alloc->mem_type = GST_ALLOCATOR_SYSMEM;

  alloc->mem_map = (GstMemoryMapFunction) _sysmem_map;

  alloc->mem_unmap = (GstMemoryUnmapFunction) _sysmem_unmap;

  alloc->mem_copy = (GstMemoryCopyFunction) _sysmem_copy;

  alloc->mem_share = (GstMemoryShareFunction) _sysmem_share;

  alloc->mem_is_span = (GstMemoryIsSpanFunction) _sysmem_is_span;

}

void

_priv_gst_allocator_initialize (void)

{

  g_rw_lock_init (&lock);

  allocators = g_hash_table_new_full (g_str_hash, g_str_equal, NULL,

      gst_object_unref);

#ifdef HAVE_GETPAGESIZE

#ifdef MEMORY_ALIGNMENT_PAGESIZE

  gst_memory_alignment = getpagesize () - 1;

#endif

#endif

  GST_CAT_DEBUG (GST_CAT_MEMORY, "memory alignment: %" G_GSIZE_FORMAT,

      gst_memory_alignment);

  _sysmem_allocator = g_object_new (gst_allocator_sysmem_get_type (), NULL);

  /* Clear floating flag */

  gst_object_ref_sink (_sysmem_allocator);

  gst_allocator_register (GST_ALLOCATOR_SYSMEM,

      gst_object_ref (_sysmem_allocator));

  _default_allocator = gst_object_ref (_sysmem_allocator);

}

void

_priv_gst_allocator_cleanup (void)

{

  gst_object_unref (_sysmem_allocator);

  _sysmem_allocator = NULL;

  gst_object_unref (_default_allocator);

  _default_allocator = NULL;

  g_clear_pointer (&allocators, g_hash_table_unref);

}

/**

 * gst_memory_new_wrapped:

 * @flags: #GstMemoryFlags

 * @data: (array length=size) (element-type guint8) (transfer none): data to

 *   wrap

 * @maxsize: allocated size of @data

 * @offset: offset in @data

 * @size: size of valid data

 * @user_data: (allow-none): user_data

 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed

 *

 * Allocate a new memory block that wraps the given @data.

 *

 * The prefix/padding must be filled with 0 if @flags contains

 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.

 *

 * Returns: (transfer full) (nullable): a new #GstMemory.

 */

GstMemory *

gst_memory_new_wrapped (GstMemoryFlags flags, gpointer data,

    gsize maxsize, gsize offset, gsize size, gpointer user_data,

    GDestroyNotify notify)

{

  GstMemorySystem *mem;

  g_return_val_if_fail (data != NULL, NULL);

  g_return_val_if_fail (offset + size <= maxsize, NULL);

  mem =

      _sysmem_new (flags, NULL, data, maxsize, 0, offset, size, user_data,

      notify);

  return (GstMemory *) mem;

}