Mon Jun 27 16:51:21 2011

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 - sizeof(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 269 of file stringfields.h.

Referenced by append_mailbox_mapping(), ast_log(), ast_manager_register2(), build_extension(), jack_data_alloc(), load_config(), load_module(), pbx_builtin_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 229 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 214 of file stringfields.h.

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

Definition at line 304 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 360 of file stringfields.h.

Referenced by __ast_channel_alloc_ap(), build_callid_pvt(), build_callid_registry(), build_contact(), build_user(), caldav_write_event(), create_addr_from_peer(), handle_request_subscribe(), init_acf_query(), load_config(), 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 384 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 247 of file stringfields.h.

Referenced by __sip_destroy(), ast_channel_destructor(), ast_custom_function_unregister(), ast_dummy_channel_destructor(), ast_manager_unregister(), ast_unregister_application(), ast_unregister_groups(), build_user(), caldav_destructor(), calendar_destructor(), calendar_event_destructor(), delete_extension(), delete_file(), 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 243 of file stringfields.h.

Referenced by __ast_channel_alloc_ap(), acf_retrieve_docs(), alloc_queue(), ast_calendar_event_alloc(), ast_dummy_channel_alloc(), 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 349 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 372 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 313 of file stringfields.h.

Referenced by 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 337 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(), 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_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(), 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(), 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(), pbx_builtin_raise_exception(), phone_new(), queue_set_param(), 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_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(), usbradio_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 298 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 1777 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.

01780 {
01781    struct ast_string_field_mgr *mgr;
01782    struct ast_string_field_pool *pool;
01783    struct ast_string_field_pool **pool_head;
01784    size_t pool_size_needed = sizeof(*pool) + pool_size;
01785    size_t size_to_alloc = optimal_alloc_size(struct_size + pool_size_needed);
01786    void *allocation;
01787    unsigned int x;
01788 
01789 #if defined(__AST_DEBUG_MALLOC)  
01790    if (!(allocation = __ast_calloc(num_structs, size_to_alloc, file, lineno, func))) {
01791       return NULL;
01792    }
01793 #else
01794    if (!(allocation = ast_calloc(num_structs, size_to_alloc))) {
01795       return NULL;
01796    }
01797 #endif
01798 
01799    for (x = 0; x < num_structs; x++) {
01800       void *base = allocation + (size_to_alloc * x);
01801       const char **p;
01802 
01803       mgr = base + field_mgr_offset;
01804       pool_head = base + field_mgr_pool_offset;
01805       pool = base + struct_size;
01806 
01807       p = (const char **) pool_head + 1;
01808       while ((struct ast_string_field_mgr *) p != mgr) {
01809          *p++ = __ast_string_field_empty;
01810       }
01811 
01812       mgr->embedded_pool = pool;
01813       *pool_head = pool;
01814       pool->size = size_to_alloc - struct_size - sizeof(*pool);
01815 #if defined(__AST_DEBUG_MALLOC)
01816       mgr->owner_file = file;
01817       mgr->owner_func = func;
01818       mgr->owner_line = lineno;
01819 #endif
01820    }
01821 
01822    return allocation;
01823 }

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 1613 of file utils.c.

References add_string_pool(), AST_STRING_FIELD_ALLOCATION, and ast_string_field_mgr::last_alloc.

Referenced by __ast_string_field_ptr_build_va().

01615 {
01616    char *result = NULL;
01617    size_t space = (*pool_head)->size - (*pool_head)->used;
01618    size_t to_alloc = needed + sizeof(ast_string_field_allocation);
01619 
01620    /* This +1 accounts for alignment on SPARC */
01621    if (__builtin_expect(to_alloc + 1 > space, 0)) {
01622       size_t new_size = (*pool_head)->size;
01623 
01624       while (new_size < to_alloc) {
01625          new_size *= 2;
01626       }
01627 
01628 #if defined(__AST_DEBUG_MALLOC)
01629       if (add_string_pool(mgr, pool_head, new_size, mgr->owner_file, mgr->owner_line, mgr->owner_func))
01630          return NULL;
01631 #else
01632       if (add_string_pool(mgr, pool_head, new_size, __FILE__, __LINE__, __FUNCTION__))
01633          return NULL;
01634 #endif
01635    }
01636 
01637    result = (*pool_head)->base + (*pool_head)->used;
01638 #ifdef __sparc__
01639    /* SPARC requires that the allocation field be aligned. */
01640    if ((long) result % sizeof(ast_string_field_allocation)) {
01641       result++;
01642       (*pool_head)->used++;
01643    }
01644 #endif
01645    (*pool_head)->used += to_alloc;
01646    (*pool_head)->active += needed;
01647    result += sizeof(ast_string_field_allocation);
01648    AST_STRING_FIELD_ALLOCATION(result) = needed;
01649    mgr->last_alloc = result;
01650 
01651    return result;
01652 }

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 1546 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.

01548 {
01549    const char **p = (const char **) pool_head + 1;
01550    struct ast_string_field_pool *cur = NULL;
01551    struct ast_string_field_pool *preserve = NULL;
01552 
01553    /* clear fields - this is always necessary */
01554    while ((struct ast_string_field_mgr *) p != mgr) {
01555       *p++ = __ast_string_field_empty;
01556    }
01557 
01558    mgr->last_alloc = NULL;
01559 #if defined(__AST_DEBUG_MALLOC)
01560    mgr->owner_file = file;
01561    mgr->owner_func = func;
01562    mgr->owner_line = lineno;
01563 #endif
01564    if (needed > 0) {    /* allocate the initial pool */
01565       *pool_head = NULL;
01566       mgr->embedded_pool = NULL;
01567       return add_string_pool(mgr, pool_head, needed, file, lineno, func);
01568    }
01569 
01570    /* if there is an embedded pool, we can't actually release *all*
01571     * pools, we must keep the embedded one. if the caller is about
01572     * to free the structure that contains the stringfield manager
01573     * and embedded pool anyway, it will be freed as part of that
01574     * operation.
01575     */
01576    if ((needed < 0) && mgr->embedded_pool) {
01577       needed = 0;
01578    }
01579 
01580    if (needed < 0) {    /* reset all pools */
01581       cur = *pool_head;
01582    } else if (mgr->embedded_pool) { /* preserve the embedded pool */
01583       preserve = mgr->embedded_pool;
01584       cur = *pool_head;
01585    } else {       /* preserve the last pool */
01586       if (*pool_head == NULL) {
01587          ast_log(LOG_WARNING, "trying to reset empty pool\n");
01588          return -1;
01589       }
01590       preserve = *pool_head;
01591       cur = preserve->prev;
01592    }
01593 
01594    if (preserve) {
01595       preserve->prev = NULL;
01596       preserve->used = preserve->active = 0;
01597    }
01598 
01599    while (cur) {
01600       struct ast_string_field_pool *prev = cur->prev;
01601 
01602       if (cur != preserve) {
01603          ast_free(cur);
01604       }
01605       cur = prev;
01606    }
01607 
01608    *pool_head = preserve;
01609 
01610    return 0;
01611 }

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 1762 of file utils.c.

References __ast_string_field_ptr_build_va().

01765 {
01766    va_list ap1, ap2;
01767 
01768    va_start(ap1, format);
01769    va_start(ap2, format);     /* va_copy does not exist on FreeBSD */
01770 
01771    __ast_string_field_ptr_build_va(mgr, pool_head, ptr, format, ap1, ap2);
01772 
01773    va_end(ap1);
01774    va_end(ap2);
01775 }

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 1697 of file utils.c.

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

Referenced by __ast_string_field_ptr_build().

01700 {
01701    size_t needed;
01702    size_t available;
01703    size_t space = (*pool_head)->size - (*pool_head)->used;
01704    ssize_t grow;
01705    char *target;
01706 
01707    /* if the field already has space allocated, try to reuse it;
01708       otherwise, try to use the empty space at the end of the current
01709       pool
01710    */
01711    if (*ptr != __ast_string_field_empty) {
01712       target = (char *) *ptr;
01713       available = AST_STRING_FIELD_ALLOCATION(*ptr);
01714       if (*ptr == mgr->last_alloc) {
01715          available += space;
01716       }
01717    } else {
01718       target = (*pool_head)->base + (*pool_head)->used + sizeof(ast_string_field_allocation);
01719 #ifdef __sparc__
01720       if ((long) target % sizeof(ast_string_field_allocation)) {
01721          target++;
01722          space--;
01723       }
01724 #endif
01725       available = space - sizeof(ast_string_field_allocation);
01726    }
01727 
01728    needed = vsnprintf(target, available, format, ap1) + 1;
01729 
01730    va_end(ap1);
01731 
01732    if (needed > available) {
01733       /* the allocation could not be satisfied using the field's current allocation
01734          (if it has one), or the space available in the pool (if it does not). allocate
01735          space for it, adding a new string pool if necessary.
01736       */
01737       if (!(target = (char *) __ast_string_field_alloc_space(mgr, pool_head, needed))) {
01738          return;
01739       }
01740       vsprintf(target, format, ap2);
01741       __ast_string_field_release_active(*pool_head, *ptr);
01742       *ptr = target;
01743    } else if (*ptr != target) {
01744       /* the allocation was satisfied using available space in the pool, but not
01745          using the space already allocated to the field
01746       */
01747       __ast_string_field_release_active(*pool_head, *ptr);
01748       mgr->last_alloc = *ptr = target;
01749       AST_STRING_FIELD_ALLOCATION(target) = needed;
01750       (*pool_head)->used += needed + sizeof(ast_string_field_allocation);
01751       (*pool_head)->active += needed;
01752    } else if ((grow = (needed - AST_STRING_FIELD_ALLOCATION(*ptr))) > 0) {
01753       /* the allocation was satisfied by using available space in the pool *and*
01754          the field was the last allocated field from the pool, so it grew
01755       */
01756       (*pool_head)->used += grow;
01757       (*pool_head)->active += grow;
01758       AST_STRING_FIELD_ALLOCATION(*ptr) += grow;
01759    }
01760 }

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 1654 of file utils.c.

References AST_STRING_FIELD_ALLOCATION, and ast_string_field_mgr::last_alloc.

01657 {
01658    ssize_t grow = needed - AST_STRING_FIELD_ALLOCATION(*ptr);
01659    size_t space = (*pool_head)->size - (*pool_head)->used;
01660 
01661    if (*ptr != mgr->last_alloc) {
01662       return 1;
01663    }
01664 
01665    if (space < grow) {
01666       return 1;
01667    }
01668 
01669    (*pool_head)->used += grow;
01670    (*pool_head)->active += grow;
01671    AST_STRING_FIELD_ALLOCATION(*ptr) += grow;
01672 
01673    return 0;
01674 }

void __ast_string_field_release_active ( struct ast_string_field_pool pool_head,
const ast_string_field  ptr 
)

Definition at line 1676 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().

01678 {
01679    struct ast_string_field_pool *pool, *prev;
01680 
01681    if (ptr == __ast_string_field_empty) {
01682       return;
01683    }
01684 
01685    for (pool = pool_head, prev = NULL; pool; prev = pool, pool = pool->prev) {
01686       if ((ptr >= pool->base) && (ptr <= (pool->base + pool->size))) {
01687          pool->active -= AST_STRING_FIELD_ALLOCATION(ptr);
01688          if ((pool->active == 0) && prev) {
01689             prev->prev = pool->prev;
01690             ast_free(pool);
01691          }
01692          break;
01693       }
01694    }
01695 }


Variable Documentation

const char* __ast_string_field_empty

Definition at line 1491 of file utils.c.

Referenced by __ast_calloc_with_stringfields(), and __ast_string_field_ptr_build_va().


Generated on Mon Jun 27 16:51:21 2011 for Asterisk - The Open Source Telephony Project by  doxygen 1.4.7