Mon Oct 8 12:39:30 2012

Asterisk developer's documentation


stringfields.h File Reference

String fields in structures. More...

#include "asterisk/inline_api.h"

Go to the source code of this file.

Data Structures

struct  ast_string_field_mgr
struct  ast_string_field_pool

Defines

#define ast_calloc_with_stringfields(n, type, size)
 Allocate a structure with embedded stringfields in a single allocation.
#define AST_DECLARE_STRING_FIELDS(field_list)
 Declare the fields needed in a structure.
#define AST_STRING_FIELD(name)   const ast_string_field name
 Declare a string field.
#define AST_STRING_FIELD_ALLOCATION(x)   *((ast_string_field_allocation *) (x - __alignof__(ast_string_field_allocation)))
 Macro to provide access to the allocation field that lives immediately in front of a string field.
#define ast_string_field_build(x, field, fmt, args...)   __ast_string_field_ptr_build(&(x)->__field_mgr, &(x)->__field_mgr_pool, (ast_string_field *) &(x)->field, fmt, args)
 Set a field to a complex (built) value.
#define ast_string_field_build_va(x, field, fmt, args1, args2)   __ast_string_field_ptr_build_va(&(x)->__field_mgr, &(x)->__field_mgr_pool, (ast_string_field *) &(x)->field, fmt, args1, args2)
 Set a field to a complex (built) value.
#define ast_string_field_free_memory(x)   __ast_string_field_init(&(x)->__field_mgr, &(x)->__field_mgr_pool, -1, __FILE__, __LINE__, __PRETTY_FUNCTION__)
 free all memory - to be called before destroying the object
#define ast_string_field_init(x, size)   __ast_string_field_init(&(x)->__field_mgr, &(x)->__field_mgr_pool, size, __FILE__, __LINE__, __PRETTY_FUNCTION__)
 Initialize a field pool and fields.
#define ast_string_field_ptr_build(x, ptr, fmt, args...)   __ast_string_field_ptr_build(&(x)->__field_mgr, &(x)->__field_mgr_pool, (ast_string_field *) ptr, fmt, args)
 Set a field to a complex (built) value.
#define ast_string_field_ptr_build_va(x, ptr, fmt, args1, args2)   __ast_string_field_ptr_build_va(&(x)->__field_mgr, &(x)->__field_mgr_pool, (ast_string_field *) ptr, fmt, args1, args2)
 Set a field to a complex (built) value with prebuilt va_lists.
#define ast_string_field_ptr_set(x, ptr, data)
 Set a field to a simple string value.
#define ast_string_field_set(x, field, data)
 Set a field to a simple string value.

Typedefs

typedef const char * ast_string_field
typedef uint16_t ast_string_field_allocation

Functions

void *attribute_malloc __ast_calloc_with_stringfields (unsigned int num_structs, size_t struct_size, size_t field_mgr_offset, size_t field_mgr_pool_offset, size_t pool_size, const char *file, int lineno, const char *func)
ast_string_field __ast_string_field_alloc_space (struct ast_string_field_mgr *mgr, struct ast_string_field_pool **pool_head, size_t needed)
int __ast_string_field_init (struct ast_string_field_mgr *mgr, struct ast_string_field_pool **pool_head, int needed, const char *file, int lineno, const char *func)
void __ast_string_field_ptr_build (struct ast_string_field_mgr *mgr, struct ast_string_field_pool **pool_head, ast_string_field *ptr, const char *format,...)
void __ast_string_field_ptr_build_va (struct ast_string_field_mgr *mgr, struct ast_string_field_pool **pool_head, ast_string_field *ptr, const char *format, va_list a1, va_list a2)
int __ast_string_field_ptr_grow (struct ast_string_field_mgr *mgr, struct ast_string_field_pool **pool_head, size_t needed, const ast_string_field *ptr)
void __ast_string_field_release_active (struct ast_string_field_pool *pool_head, const ast_string_field ptr)

Variables

const char * __ast_string_field_empty


Detailed Description

String fields in structures.

This file contains objects and macros used to manage string fields in structures without requiring them to be allocated as fixed-size buffers or requiring individual allocations for for each field.

Using this functionality is quite simple. An example structure with three fields is defined like this:

  struct sample_fields {
     int x1;
     AST_DECLARE_STRING_FIELDS(
        AST_STRING_FIELD(foo);
        AST_STRING_FIELD(bar);
        AST_STRING_FIELD(blah);
     );
     long x2;
  };

When an instance of this structure is allocated (either statically or dynamically), the fields and the pool of storage for them must be initialized:

  struct sample_fields *x;
  
  x = ast_calloc(1, sizeof(*x));
  if (x == NULL || ast_string_field_init(x, 252)) {
   if (x)
      ast_free(x);
   x = NULL;
   ... handle error
  }

Fields will default to pointing to an empty string, and will revert to that when ast_string_field_set() is called with a NULL argument. A string field will never contain NULL.

ast_string_field_init(x, 0) will reset fields to the initial value while keeping the pool allocated.

Reading the fields is much like using 'const char * const' fields in the structure: you cannot write to the field or to the memory it points to.

Writing to the fields must be done using the wrapper macros listed below; and assignments are always by value (i.e. strings are copied): ast_string_field_set() stores a simple value; ast_string_field_build() builds the string using a printf-style format; ast_string_field_build_va() is the varargs version of the above (for portability reasons it uses two vararg arguments); variants of these function allow passing a pointer to the field as an argument.

  ast_string_field_set(x, foo, "infinite loop");
  ast_string_field_set(x, foo, NULL); // set to an empty string
  ast_string_field_ptr_set(x, &x->bar, "right way");

  ast_string_field_build(x, blah, "%d %s", zipcode, city);
  ast_string_field_ptr_build(x, &x->blah, "%d %s", zipcode, city);

  ast_string_field_build_va(x, bar, fmt, args1, args2)
  ast_string_field_ptr_build_va(x, &x->bar, fmt, args1, args2)

When the structure instance is no longer needed, the fields and their storage pool must be freed:

  ast_string_field_free_memory(x);
  ast_free(x);

This completes the API description.

Definition in file stringfields.h.


Define Documentation

#define ast_calloc_with_stringfields ( n,
type,
size   ) 

Value:

__ast_calloc_with_stringfields(n, sizeof(type), offsetof(type, __field_mgr), offsetof(type, __field_mgr_pool), \
                   size, __FILE__, __LINE__, __PRETTY_FUNCTION__)
Allocate a structure with embedded stringfields in a single allocation.

Parameters:
n Number of structures to allocate (see ast_calloc)
type The type of structure to allocate
size The number of bytes of space (minimum) to allocate for stringfields to use
This function will allocate memory for one or more structures that use stringfields, and also allocate space for the stringfields and initialize the stringfield management structure embedded in the outer structure.

Since:
1.8

Definition at line 275 of file stringfields.h.

Referenced by append_mailbox_mapping(), ast_log(), AST_TEST_DEFINE(), build_extension(), jack_data_alloc(), load_config(), load_module(), raise_exception(), register_group(), register_group_feature(), sip_register(), sip_subscribe_mwi(), sla_build_station(), and sla_build_trunk().

#define AST_DECLARE_STRING_FIELDS ( field_list   ) 

Value:

struct ast_string_field_pool *__field_mgr_pool; \
   field_list              \
   struct ast_string_field_mgr __field_mgr
Declare the fields needed in a structure.

Parameters:
field_list The list of fields to declare, using AST_STRING_FIELD() for each one. Internally, string fields are stored as a pointer to the head of the pool, followed by individual string fields, and then a struct ast_string_field_mgr which describes the space allocated. We split the two variables so they can be used as markers around the field_list, and this allows us to determine how many entries are in the field, and play with them. In particular, for writing to the fields, we rely on __field_mgr_pool to be a non-const pointer, so we know it has the same size as ast_string_field, and we can use it to locate the fields.

Definition at line 235 of file stringfields.h.

#define AST_STRING_FIELD ( name   )     const ast_string_field name

Declare a string field.

Parameters:
name The field name

Definition at line 220 of file stringfields.h.

#define AST_STRING_FIELD_ALLOCATION (  )     *((ast_string_field_allocation *) (x - __alignof__(ast_string_field_allocation)))

Macro to provide access to the allocation field that lives immediately in front of a string field.

Parameters:
x Pointer to the string field
Note that x must be a pointer to a byte-sized type -- normally (char *) -- or this calculation would break horribly

Definition at line 309 of file stringfields.h.

Referenced by __ast_string_field_alloc_space(), __ast_string_field_ptr_build_va(), __ast_string_field_ptr_grow(), and __ast_string_field_release_active().

#define ast_string_field_build ( x,
field,
fmt,
args...   )     __ast_string_field_ptr_build(&(x)->__field_mgr, &(x)->__field_mgr_pool, (ast_string_field *) &(x)->field, fmt, args)

Set a field to a complex (built) value.

Parameters:
x Pointer to a structure containing fields
field Name of the field to set
fmt printf-style format string
args Arguments for format string
Returns:
nothing

Definition at line 365 of file stringfields.h.

Referenced by __ast_channel_alloc_ap(), action_originate(), build_callid_pvt(), build_callid_registry(), build_contact(), build_user(), caldav_write_event(), handle_request_subscribe(), init_acf_query(), load_config(), make_our_tag(), parse_cdata(), parse_moved_contact(), parse_register_contact(), set_nonce_randdata(), sip_sendhtml(), sip_sipredirect(), and t30_phase_e_handler().

#define ast_string_field_build_va ( x,
field,
fmt,
args1,
args2   )     __ast_string_field_ptr_build_va(&(x)->__field_mgr, &(x)->__field_mgr_pool, (ast_string_field *) &(x)->field, fmt, args1, args2)

Set a field to a complex (built) value.

Parameters:
x Pointer to a structure containing fields
field Name of the field to set
fmt printf-style format string
args1 argument one
args2 argument two
Returns:
nothing

Definition at line 389 of file stringfields.h.

Referenced by __ast_channel_alloc_ap().

#define ast_string_field_free_memory (  )     __ast_string_field_init(&(x)->__field_mgr, &(x)->__field_mgr_pool, -1, __FILE__, __LINE__, __PRETTY_FUNCTION__)

free all memory - to be called before destroying the object

Definition at line 253 of file stringfields.h.

Referenced by __sip_destroy(), action_destroy(), ast_channel_destructor(), ast_custom_function_unregister(), ast_dummy_channel_destructor(), ast_pbx_outgoing_app(), ast_pbx_run_app(), AST_TEST_DEFINE(), ast_unregister_application(), ast_unregister_groups(), build_user(), caldav_destructor(), calendar_destructor(), calendar_event_destructor(), delete_extension(), delete_file(), destroy_fast_originate_helper(), destroy_jack_data(), destroy_mailbox_mapping(), destroy_queue(), destroy_session_details(), destroy_station(), destroy_trunk(), ewscal_destructor(), exception_store_free(), exchangecal_destructor(), free_acf_query(), free_outgoing(), icalendar_destructor(), init_acf_query(), load_module(), peer_destructor(), profile_destructor(), pvt_destructor(), realtime_multi_odbc(), realtime_odbc(), route_destructor(), sip_destroy_peer(), sip_monitor_instance_destructor(), sip_registry_destroy(), sip_subscribe_mwi_destroy(), tds_unload_module(), temp_pvt_cleanup(), update_odbc(), and user_destructor().

#define ast_string_field_init ( x,
size   )     __ast_string_field_init(&(x)->__field_mgr, &(x)->__field_mgr_pool, size, __FILE__, __LINE__, __PRETTY_FUNCTION__)

Initialize a field pool and fields.

Parameters:
x Pointer to a structure containing fields
size Amount of storage to allocate. Use 0 to reset fields to the default value, and release all but the most recent pool. size<0 (used internally) means free all pools.
Returns:
0 on success, non-zero on failure

Definition at line 249 of file stringfields.h.

Referenced by __ast_channel_alloc_ap(), acf_retrieve_docs(), action_originate(), alloc_queue(), ast_calendar_event_alloc(), ast_dummy_channel_alloc(), ast_manager_register2(), ast_pbx_outgoing_app(), ast_register_application2(), build_calendar(), build_peer(), build_profile(), build_route(), build_user(), caldav_load_calendar(), ewscal_load_calendar(), exchangecal_load_calendar(), ical_load_calendar(), init_acf_query(), init_outgoing(), init_pvt(), new_iax(), realtime_multi_odbc(), realtime_odbc(), session_details_new(), sip_alloc(), sip_monitor_instance_init(), tds_load_module(), temp_peer(), temp_pvt_init(), transmit_response_using_temp(), and update_odbc().

#define ast_string_field_ptr_build ( x,
ptr,
fmt,
args...   )     __ast_string_field_ptr_build(&(x)->__field_mgr, &(x)->__field_mgr_pool, (ast_string_field *) ptr, fmt, args)

Set a field to a complex (built) value.

Parameters:
x Pointer to a structure containing fields
ptr Pointer to a field within the structure
fmt printf-style format string
args Arguments for format string
Returns:
nothing

Definition at line 354 of file stringfields.h.

#define ast_string_field_ptr_build_va ( x,
ptr,
fmt,
args1,
args2   )     __ast_string_field_ptr_build_va(&(x)->__field_mgr, &(x)->__field_mgr_pool, (ast_string_field *) ptr, fmt, args1, args2)

Set a field to a complex (built) value with prebuilt va_lists.

Parameters:
x Pointer to a structure containing fields
ptr Pointer to a field within the structure
fmt printf-style format string
args1 Arguments for format string in va_list format
args2 a second copy of the va_list for the sake of bsd, with no va_list copy operation
Returns:
nothing

Definition at line 377 of file stringfields.h.

#define ast_string_field_ptr_set ( x,
ptr,
data   ) 

Set a field to a simple string value.

Parameters:
x Pointer to a structure containing fields
ptr Pointer to a field within the structure
data String value to be copied into the field
Returns:
nothing

Definition at line 318 of file stringfields.h.

Referenced by ast_parse_digest(), and reply_digest().

#define ast_string_field_set ( x,
field,
data   ) 

Value:

do {     \
   ast_string_field_ptr_set(x, &(x)->field, data);    \
   } while (0)
Set a field to a simple string value.

Parameters:
x Pointer to a structure containing fields
field Name of the field to set
data String value to be copied into the field
Returns:
nothing

Definition at line 342 of file stringfields.h.

Referenced by __ast_change_name_nolink(), __ast_channel_alloc_ap(), __find_callno(), __oh323_new(), __sip_subscribe_mwi_do(), acf_faxopt_write(), acf_retrieve_docs(), action_originate(), agent_new(), alloc_queue(), alsa_new(), analog_new_ast_channel(), append_mailbox_mapping(), apply_outgoing(), ast_call_forward(), ast_cdr_setaccount(), ast_cdr_setpeeraccount(), ast_cel_fabricate_channel_from_event(), ast_channel_change_linkedid(), ast_do_masquerade(), ast_iax2_new(), ast_log(), ast_manager_register2(), ast_parse_digest(), ast_pbx_outgoing_app(), ast_register_application2(), ast_set_hangupsource(), ast_set_owners_and_peers(), authenticate_reply(), authenticate_request(), authenticate_verify(), begin_dial_channel(), build_calendar(), build_extension(), build_peer(), build_profile(), build_route(), build_user(), cache_get_callno_locked(), caldav_add_event(), caldav_load_calendar(), calendar_write_exec(), change_callid_pvt(), check_access(), check_peer_ok(), check_user_full(), conf_start_moh(), console_new(), copy_event_data(), create_addr(), create_addr_from_peer(), custom_prepare(), dahdi_new(), dial_exec_full(), do_forward(), endelm(), ewscal_load_calendar(), exchangecal_load_calendar(), extract_uri(), feature_request_and_dial(), findmeexec(), generic_fax_exec(), get_also_info(), get_destination(), get_pai(), get_realm(), get_rpid(), gtalk_new(), handle_cc_notify(), handle_incoming(), handle_options(), handle_request_bye(), handle_request_invite(), handle_request_options(), handle_request_publish(), handle_request_refer(), handle_response(), handle_response_invite(), handle_response_notify(), handle_response_publish(), handle_response_subscribe(), iax2_call(), iax2_request(), iax_park(), ical_load_calendar(), icalendar_add_event(), init_acf_query(), init_pvt(), init_queue(), initreqprep(), jingle_new(), load_config(), local_call(), logger_print_normal(), mgcp_new(), misdn_facility_ie_handler(), moh_handle_digit(), monitor_dial(), nbs_new(), new_iax(), oss_new(), parse_moved_contact(), parse_ok_contact(), parse_register_contact(), phone_new(), queue_set_param(), raise_exception(), read_config(), receivefax_exec(), reg_source_db(), register_group(), register_group_feature(), register_verify(), registry_authrequest(), reply_digest(), reqprep(), respprep(), ring_entry(), save_osptoken(), sendfax_exec(), set_moh_exec(), set_peer_defaults(), set_pvt_defaults(), sig_pri_handle_subcmds(), sip_alloc(), sip_call(), sip_monitor_instance_init(), sip_new(), sip_park(), sip_parse_register_line(), sip_poke_peer(), sip_request_call(), sip_send_mwi_to_peer(), sip_set_redirstr(), sip_subscribe_mwi(), skinny_new(), sla_build_station(), sla_build_trunk(), socket_process(), startelm(), store_callerid(), t30_phase_e_handler(), tds_load_module(), transmit_refer(), transmit_register(), transmit_response_using_temp(), unistim_new(), vm_execmain(), and wait_for_answer().


Typedef Documentation

typedef const char* ast_string_field

Definition at line 115 of file stringfields.h.

typedef uint16_t ast_string_field_allocation

Definition at line 119 of file stringfields.h.


Function Documentation

void* attribute_malloc __ast_calloc_with_stringfields ( unsigned int  num_structs,
size_t  struct_size,
size_t  field_mgr_offset,
size_t  field_mgr_pool_offset,
size_t  pool_size,
const char *  file,
int  lineno,
const char *  func 
)

Definition at line 1807 of file utils.c.

References __ast_calloc(), __ast_string_field_empty, allocation, ast_calloc, ast_string_field_pool::base, ast_string_field_mgr::embedded_pool, optimal_alloc_size(), and ast_string_field_pool::size.

01810 {
01811    struct ast_string_field_mgr *mgr;
01812    struct ast_string_field_pool *pool;
01813    struct ast_string_field_pool **pool_head;
01814    size_t pool_size_needed = sizeof(*pool) + pool_size;
01815    size_t size_to_alloc = optimal_alloc_size(struct_size + pool_size_needed);
01816    void *allocation;
01817    unsigned int x;
01818 
01819 #if defined(__AST_DEBUG_MALLOC)  
01820    if (!(allocation = __ast_calloc(num_structs, size_to_alloc, file, lineno, func))) {
01821       return NULL;
01822    }
01823 #else
01824    if (!(allocation = ast_calloc(num_structs, size_to_alloc))) {
01825       return NULL;
01826    }
01827 #endif
01828 
01829    for (x = 0; x < num_structs; x++) {
01830       void *base = allocation + (size_to_alloc * x);
01831       const char **p;
01832 
01833       mgr = base + field_mgr_offset;
01834       pool_head = base + field_mgr_pool_offset;
01835       pool = base + struct_size;
01836 
01837       p = (const char **) pool_head + 1;
01838       while ((struct ast_string_field_mgr *) p != mgr) {
01839          *p++ = __ast_string_field_empty;
01840       }
01841 
01842       mgr->embedded_pool = pool;
01843       *pool_head = pool;
01844       pool->size = size_to_alloc - struct_size - sizeof(*pool);
01845 #if defined(__AST_DEBUG_MALLOC)
01846       mgr->owner_file = file;
01847       mgr->owner_func = func;
01848       mgr->owner_line = lineno;
01849 #endif
01850    }
01851 
01852    return allocation;
01853 }

ast_string_field __ast_string_field_alloc_space ( struct ast_string_field_mgr mgr,
struct ast_string_field_pool **  pool_head,
size_t  needed 
)

Definition at line 1648 of file utils.c.

References add_string_pool(), ast_alignof, ast_assert, ast_make_room_for, AST_STRING_FIELD_ALLOCATION, and ast_string_field_mgr::last_alloc.

Referenced by __ast_string_field_ptr_build_va().

01650 {
01651    char *result = NULL;
01652    size_t space = (*pool_head)->size - (*pool_head)->used;
01653    size_t to_alloc;
01654 
01655    /* Make room for ast_string_field_allocation and make it a multiple of that. */
01656    to_alloc = ast_make_room_for(needed, ast_string_field_allocation);
01657    ast_assert(to_alloc % ast_alignof(ast_string_field_allocation) == 0);
01658 
01659    if (__builtin_expect(to_alloc > space, 0)) {
01660       size_t new_size = (*pool_head)->size;
01661 
01662       while (new_size < to_alloc) {
01663          new_size *= 2;
01664       }
01665 
01666 #if defined(__AST_DEBUG_MALLOC)
01667       if (add_string_pool(mgr, pool_head, new_size, mgr->owner_file, mgr->owner_line, mgr->owner_func))
01668          return NULL;
01669 #else
01670       if (add_string_pool(mgr, pool_head, new_size, __FILE__, __LINE__, __FUNCTION__))
01671          return NULL;
01672 #endif
01673    }
01674 
01675    /* pool->base is always aligned (gcc aligned attribute). We ensure that
01676     * to_alloc is also a multiple of ast_alignof(ast_string_field_allocation)
01677     * causing result to always be aligned as well; which in turn fixes that
01678     * AST_STRING_FIELD_ALLOCATION(result) is aligned. */
01679    result = (*pool_head)->base + (*pool_head)->used;
01680    (*pool_head)->used += to_alloc;
01681    (*pool_head)->active += needed;
01682    result += ast_alignof(ast_string_field_allocation);
01683    AST_STRING_FIELD_ALLOCATION(result) = needed;
01684    mgr->last_alloc = result;
01685 
01686    return result;
01687 }

int __ast_string_field_init ( struct ast_string_field_mgr mgr,
struct ast_string_field_pool **  pool_head,
int  needed,
const char *  file,
int  lineno,
const char *  func 
)

Definition at line 1581 of file utils.c.

References ast_string_field_pool::active, add_string_pool(), ast_free, ast_log(), ast_string_field_mgr::embedded_pool, ast_string_field_mgr::last_alloc, LOG_WARNING, ast_string_field_pool::prev, and ast_string_field_pool::used.

01583 {
01584    const char **p = (const char **) pool_head + 1;
01585    struct ast_string_field_pool *cur = NULL;
01586    struct ast_string_field_pool *preserve = NULL;
01587 
01588    /* clear fields - this is always necessary */
01589    while ((struct ast_string_field_mgr *) p != mgr) {
01590       *p++ = __ast_string_field_empty;
01591    }
01592 
01593    mgr->last_alloc = NULL;
01594 #if defined(__AST_DEBUG_MALLOC)
01595    mgr->owner_file = file;
01596    mgr->owner_func = func;
01597    mgr->owner_line = lineno;
01598 #endif
01599    if (needed > 0) {    /* allocate the initial pool */
01600       *pool_head = NULL;
01601       mgr->embedded_pool = NULL;
01602       return add_string_pool(mgr, pool_head, needed, file, lineno, func);
01603    }
01604 
01605    /* if there is an embedded pool, we can't actually release *all*
01606     * pools, we must keep the embedded one. if the caller is about
01607     * to free the structure that contains the stringfield manager
01608     * and embedded pool anyway, it will be freed as part of that
01609     * operation.
01610     */
01611    if ((needed < 0) && mgr->embedded_pool) {
01612       needed = 0;
01613    }
01614 
01615    if (needed < 0) {    /* reset all pools */
01616       cur = *pool_head;
01617    } else if (mgr->embedded_pool) { /* preserve the embedded pool */
01618       preserve = mgr->embedded_pool;
01619       cur = *pool_head;
01620    } else {       /* preserve the last pool */
01621       if (*pool_head == NULL) {
01622          ast_log(LOG_WARNING, "trying to reset empty pool\n");
01623          return -1;
01624       }
01625       preserve = *pool_head;
01626       cur = preserve->prev;
01627    }
01628 
01629    if (preserve) {
01630       preserve->prev = NULL;
01631       preserve->used = preserve->active = 0;
01632    }
01633 
01634    while (cur) {
01635       struct ast_string_field_pool *prev = cur->prev;
01636 
01637       if (cur != preserve) {
01638          ast_free(cur);
01639       }
01640       cur = prev;
01641    }
01642 
01643    *pool_head = preserve;
01644 
01645    return 0;
01646 }

void __ast_string_field_ptr_build ( struct ast_string_field_mgr mgr,
struct ast_string_field_pool **  pool_head,
ast_string_field ptr,
const char *  format,
  ... 
)

Definition at line 1792 of file utils.c.

References __ast_string_field_ptr_build_va().

01795 {
01796    va_list ap1, ap2;
01797 
01798    va_start(ap1, format);
01799    va_start(ap2, format);     /* va_copy does not exist on FreeBSD */
01800 
01801    __ast_string_field_ptr_build_va(mgr, pool_head, ptr, format, ap1, ap2);
01802 
01803    va_end(ap1);
01804    va_end(ap2);
01805 }

void __ast_string_field_ptr_build_va ( struct ast_string_field_mgr mgr,
struct ast_string_field_pool **  pool_head,
ast_string_field ptr,
const char *  format,
va_list  a1,
va_list  a2 
)

Definition at line 1732 of file utils.c.

References __ast_string_field_alloc_space(), __ast_string_field_empty, __ast_string_field_release_active(), ast_align_for, ast_alignof, ast_make_room_for, AST_STRING_FIELD_ALLOCATION, available(), and ast_string_field_mgr::last_alloc.

Referenced by __ast_string_field_ptr_build().

01735 {
01736    size_t needed;
01737    size_t available;
01738    size_t space = (*pool_head)->size - (*pool_head)->used;
01739    ssize_t grow;
01740    char *target;
01741 
01742    /* if the field already has space allocated, try to reuse it;
01743       otherwise, try to use the empty space at the end of the current
01744       pool
01745    */
01746    if (*ptr != __ast_string_field_empty) {
01747       target = (char *) *ptr;
01748       available = AST_STRING_FIELD_ALLOCATION(*ptr);
01749       if (*ptr == mgr->last_alloc) {
01750          available += space;
01751       }
01752    } else {
01753       /* pool->used is always a multiple of ast_alignof(ast_string_field_allocation)
01754        * so we don't need to re-align anything here.
01755        */
01756       target = (*pool_head)->base + (*pool_head)->used + ast_alignof(ast_string_field_allocation);
01757       available = space - ast_alignof(ast_string_field_allocation);
01758    }
01759 
01760    needed = vsnprintf(target, available, format, ap1) + 1;
01761 
01762    if (needed > available) {
01763       /* the allocation could not be satisfied using the field's current allocation
01764          (if it has one), or the space available in the pool (if it does not). allocate
01765          space for it, adding a new string pool if necessary.
01766       */
01767       if (!(target = (char *) __ast_string_field_alloc_space(mgr, pool_head, needed))) {
01768          return;
01769       }
01770       vsprintf(target, format, ap2);
01771       __ast_string_field_release_active(*pool_head, *ptr);
01772       *ptr = target;
01773    } else if (*ptr != target) {
01774       /* the allocation was satisfied using available space in the pool, but not
01775          using the space already allocated to the field
01776       */
01777       __ast_string_field_release_active(*pool_head, *ptr);
01778       mgr->last_alloc = *ptr = target;
01779       AST_STRING_FIELD_ALLOCATION(target) = needed;
01780       (*pool_head)->used += ast_make_room_for(needed, ast_string_field_allocation);
01781       (*pool_head)->active += needed;
01782    } else if ((grow = (needed - AST_STRING_FIELD_ALLOCATION(*ptr))) > 0) {
01783       /* the allocation was satisfied by using available space in the pool *and*
01784          the field was the last allocated field from the pool, so it grew
01785       */
01786       AST_STRING_FIELD_ALLOCATION(*ptr) += grow;
01787       (*pool_head)->used += ast_align_for(grow, ast_string_field_allocation);
01788       (*pool_head)->active += grow;
01789    }
01790 }

int __ast_string_field_ptr_grow ( struct ast_string_field_mgr mgr,
struct ast_string_field_pool **  pool_head,
size_t  needed,
const ast_string_field ptr 
)

Definition at line 1689 of file utils.c.

References AST_STRING_FIELD_ALLOCATION, and ast_string_field_mgr::last_alloc.

01692 {
01693    ssize_t grow = needed - AST_STRING_FIELD_ALLOCATION(*ptr);
01694    size_t space = (*pool_head)->size - (*pool_head)->used;
01695 
01696    if (*ptr != mgr->last_alloc) {
01697       return 1;
01698    }
01699 
01700    if (space < grow) {
01701       return 1;
01702    }
01703 
01704    (*pool_head)->used += grow;
01705    (*pool_head)->active += grow;
01706    AST_STRING_FIELD_ALLOCATION(*ptr) += grow;
01707 
01708    return 0;
01709 }

void __ast_string_field_release_active ( struct ast_string_field_pool pool_head,
const ast_string_field  ptr 
)

Definition at line 1711 of file utils.c.

References ast_string_field_pool::active, ast_free, AST_STRING_FIELD_ALLOCATION, and ast_string_field_pool::prev.

Referenced by __ast_string_field_ptr_build_va().

01713 {
01714    struct ast_string_field_pool *pool, *prev;
01715 
01716    if (ptr == __ast_string_field_empty) {
01717       return;
01718    }
01719 
01720    for (pool = pool_head, prev = NULL; pool; prev = pool, pool = pool->prev) {
01721       if ((ptr >= pool->base) && (ptr <= (pool->base + pool->size))) {
01722          pool->active -= AST_STRING_FIELD_ALLOCATION(ptr);
01723          if ((pool->active == 0) && prev) {
01724             prev->prev = pool->prev;
01725             ast_free(pool);
01726          }
01727          break;
01728       }
01729    }
01730 }


Variable Documentation

const char* __ast_string_field_empty

Definition at line 1526 of file utils.c.

Referenced by __ast_calloc_with_stringfields(), and __ast_string_field_ptr_build_va().


Generated on Mon Oct 8 12:39:30 2012 for Asterisk - The Open Source Telephony Project by  doxygen 1.4.7