conyon44

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+/* Copyright (c) 2000, 2021, Oracle and/or its affiliates.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License, version 2.0,
+   as published by the Free Software Foundation.
+
+   This program is also distributed with certain software (including
+   but not limited to OpenSSL) that is licensed under separate terms,
+   as designated in a particular file or component or in included license
+   documentation.  The authors of MySQL hereby grant you an additional
+   permission to link the program and your derivative works with the
+   separately licensed software that they have included with MySQL.
+
+   Without limiting anything contained in the foregoing, this file,
+   which is part of C Driver for MySQL (Connector/C), is also subject to the
+   Universal FOSS Exception, version 1.0, a copy of which can be found at
+   http://oss.oracle.com/licenses/universal-foss-exception.
+
+   This program 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, version 2.0, for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+/* Handling of arrays that can grow dynamicly. */
+
+#include "mysys_priv.h"
+#include "m_string.h"
+#include "my_sys.h"
+
+/*
+  Initiate dynamic array
+
+  SYNOPSIS
+    my_init_dynamic_array()
+      array		Pointer to an array
+      element_size	Size of element
+      init_buffer       Initial buffer pointer
+      init_alloc	Number of initial elements
+      alloc_increment	Increment for adding new elements
+
+  DESCRIPTION
+    init_dynamic_array() initiates array and allocate space for 
+    init_alloc eilements. 
+    Array is usable even if space allocation failed, hence, the
+    function never returns TRUE.
+    Static buffers must begin immediately after the array structure.
+
+  RETURN VALUE
+    FALSE	Ok
+*/
+
+my_bool my_init_dynamic_array(DYNAMIC_ARRAY *array,
+                              PSI_memory_key psi_key,
+                              uint element_size,
+                              void *init_buffer,
+                              uint init_alloc,
+                              uint alloc_increment)
+{
+  DBUG_ENTER("init_dynamic_array");
+  if (!alloc_increment)
+  {
+    alloc_increment=MY_MAX((8192-MALLOC_OVERHEAD)/element_size,16);
+    if (init_alloc > 8 && alloc_increment > init_alloc * 2)
+      alloc_increment=init_alloc*2;
+  }
+
+  if (!init_alloc)
+  {
+    init_alloc=alloc_increment;
+    init_buffer= 0;
+  }
+  array->elements=0;
+  array->max_element=init_alloc;
+  array->alloc_increment=alloc_increment;
+  array->size_of_element=element_size;
+  array->m_psi_key= psi_key;
+  if ((array->buffer= init_buffer))
+    DBUG_RETURN(FALSE);
+  /* 
+    Since the dynamic array is usable even if allocation fails here malloc
+    should not throw an error
+  */
+  if (!(array->buffer= (uchar*) my_malloc(psi_key,
+                                          element_size*init_alloc, MYF(0))))
+    array->max_element=0;
+  DBUG_RETURN(FALSE);
+} 
+
+my_bool init_dynamic_array(DYNAMIC_ARRAY *array, uint element_size,
+                           uint init_alloc, uint alloc_increment)
+{
+  /* placeholder to preserve ABI */
+  return my_init_dynamic_array(array,
+                               PSI_INSTRUMENT_ME,
+                               element_size,
+                               NULL,              /* init_buffer */
+                               init_alloc, 
+                               alloc_increment);
+}
+/*
+  Insert element at the end of array. Allocate memory if needed.
+
+  SYNOPSIS
+    insert_dynamic()
+      array
+      element
+
+  RETURN VALUE
+    TRUE	Insert failed
+    FALSE	Ok
+*/
+
+my_bool insert_dynamic(DYNAMIC_ARRAY *array, const void *element)
+{
+  uchar* buffer;
+  if (array->elements == array->max_element)
+  {						/* Call only when nessesary */
+    if (!(buffer=alloc_dynamic(array)))
+      return TRUE;
+  }
+  else
+  {
+    buffer=array->buffer+(array->elements * array->size_of_element);
+    array->elements++;
+  }
+  memcpy(buffer,element,(size_t) array->size_of_element);
+  return FALSE;
+}
+
+
+/*
+  Alloc space for next element(s) 
+
+  SYNOPSIS
+    alloc_dynamic()
+      array
+
+  DESCRIPTION
+    alloc_dynamic() checks if there is empty space for at least
+    one element if not tries to allocate space for alloc_increment
+    elements at the end of array.
+
+  RETURN VALUE
+    pointer	Pointer to empty space for element
+    0		Error
+*/
+
+void *alloc_dynamic(DYNAMIC_ARRAY *array)
+{
+  if (array->elements == array->max_element)
+  {
+    char *new_ptr;
+    if (array->buffer == (uchar *)(array + 1))
+    {
+      /*
+        In this senerio, the buffer is statically preallocated,
+        so we have to create an all-new malloc since we overflowed
+      */
+      if (!(new_ptr= (char *) my_malloc(array->m_psi_key,
+                                        (array->max_element+
+                                         array->alloc_increment) *
+                                        array->size_of_element,
+                                        MYF(MY_WME))))
+        return 0;
+      memcpy(new_ptr, array->buffer, 
+             array->elements * array->size_of_element);
+    }
+    else
+    if (!(new_ptr=(char*) my_realloc(array->m_psi_key,
+                                     array->buffer,(array->max_element+
+                                     array->alloc_increment)*
+                                     array->size_of_element,
+                                     MYF(MY_WME | MY_ALLOW_ZERO_PTR))))
+      return 0;
+    array->buffer= (uchar*) new_ptr;
+    array->max_element+=array->alloc_increment;
+  }
+  return array->buffer+(array->elements++ * array->size_of_element);
+}
+
+
+/*
+  Pop last element from array.
+
+  SYNOPSIS
+    pop_dynamic()
+      array
+  
+  RETURN VALUE    
+    pointer	Ok
+    0		Array is empty
+*/
+
+void *pop_dynamic(DYNAMIC_ARRAY *array)
+{
+  if (array->elements)
+    return array->buffer+(--array->elements * array->size_of_element);
+  return 0;
+}
+
+
+/*
+  Get an element from array by given index
+
+  SYNOPSIS
+    get_dynamic()
+      array	
+      uchar*	Element to be returned. If idx > elements contain zeroes.
+      idx	Index of element wanted. 
+*/
+
+void get_dynamic(DYNAMIC_ARRAY *array, void *element, uint idx)
+{
+  if (idx >= array->elements)
+  {
+    DBUG_PRINT("warning",("To big array idx: %d, array size is %d",
+                          idx,array->elements));
+    memset(element, 0, array->size_of_element);
+    return;
+  }
+  memcpy(element,array->buffer+idx*array->size_of_element,
+         (size_t) array->size_of_element);
+}
+
+void claim_dynamic(DYNAMIC_ARRAY *array)
+{
+  /*
+    Check for a static buffer
+  */
+  if (array->buffer == (uchar *)(array + 1))
+    return;
+
+  my_claim(array->buffer);
+}
+
+
+/*
+  Empty array by freeing all memory
+
+  SYNOPSIS
+    delete_dynamic()
+      array	Array to be deleted
+*/
+
+void delete_dynamic(DYNAMIC_ARRAY *array)
+{
+  /*
+    Just mark as empty if we are using a static buffer
+  */
+  if (array->buffer == (uchar *)(array + 1))
+    array->elements= 0;
+  else
+  if (array->buffer)
+  {
+    my_free(array->buffer);
+    array->buffer=0;
+    array->elements=array->max_element=0;
+  }
+}
+
+
+/*
+  Free unused memory
+
+  SYNOPSIS
+    freeze_size()
+      array	Array to be freed
+
+*/
+
+void freeze_size(DYNAMIC_ARRAY *array)
+{
+  uint elements=MY_MAX(array->elements,1);
+
+  /*
+    Do nothing if we are using a static buffer
+  */
+  if (array->buffer == (uchar *)(array + 1))
+    return;
+    
+  if (array->buffer && array->max_element != elements)
+  {
+    array->buffer=(uchar*) my_realloc(array->m_psi_key,
+                                      array->buffer,
+                                     elements*array->size_of_element,
+                                     MYF(MY_WME));
+    array->max_element=elements;
+  }
+}