Tue Aug 20 16:35:16 2013

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(), build_profile(), 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_profile(), 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__)
#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(), __ast_dummy_channel_alloc(), acf_retrieve_docs(), action_originate(), alloc_queue(), ast_calendar_event_alloc(), ast_manager_register2(), ast_pbx_outgoing_app(), ast_register_application2(), auth_http_callback(), 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_pvt(), new_iax(), new_outgoing(), 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(), disa_exec(), 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(), load_module(), local_call(), logger_print_normal(), mgcp_new(), misdn_facility_ie_handler(), moh_handle_digit(), monitor_dial(), nbs_new(), new_iax(), new_outgoing(), 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(), sip_alloc(), sip_call(), sip_monitor_instance_init(), sip_new(), sip_park(), sip_parse_register_line(), sip_poke_peer(), sip_reload(), 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 1888 of file utils.c.

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

01891 {
01892    struct ast_string_field_mgr *mgr;
01893    struct ast_string_field_pool *pool;
01894    struct ast_string_field_pool **pool_head;
01895    size_t pool_size_needed = sizeof(*pool) + pool_size;
01896    size_t size_to_alloc = optimal_alloc_size(struct_size + pool_size_needed);
01897    void *allocation;
01898    unsigned int x;
01899 
01900 #if defined(__AST_DEBUG_MALLOC)  
01901    if (!(allocation = __ast_calloc(num_structs, size_to_alloc, file, lineno, func))) {
01902       return NULL;
01903    }
01904 #else
01905    if (!(allocation = ast_calloc(num_structs, size_to_alloc))) {
01906       return NULL;
01907    }
01908 #endif
01909 
01910    for (x = 0; x < num_structs; x++) {
01911       void *base = allocation + (size_to_alloc * x);
01912       const char **p;
01913 
01914       mgr = base + field_mgr_offset;
01915       pool_head = base + field_mgr_pool_offset;
01916       pool = base + struct_size;
01917 
01918       p = (const char **) pool_head + 1;
01919       while ((struct ast_string_field_mgr *) p != mgr) {
01920          *p++ = __ast_string_field_empty;
01921       }
01922 
01923       mgr->embedded_pool = pool;
01924       *pool_head = pool;
01925       pool->size = size_to_alloc - struct_size - sizeof(*pool);
01926 #if defined(__AST_DEBUG_MALLOC)
01927       mgr->owner_file = file;
01928       mgr->owner_func = func;
01929       mgr->owner_line = lineno;
01930 #endif
01931    }
01932 
01933    return allocation;
01934 }

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 1729 of file utils.c.

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

Referenced by __ast_string_field_ptr_build_va().

01731 {
01732    char *result = NULL;
01733    size_t space = (*pool_head)->size - (*pool_head)->used;
01734    size_t to_alloc;
01735 
01736    /* Make room for ast_string_field_allocation and make it a multiple of that. */
01737    to_alloc = ast_make_room_for(needed, ast_string_field_allocation);
01738    ast_assert(to_alloc % ast_alignof(ast_string_field_allocation) == 0);
01739 
01740    if (__builtin_expect(to_alloc > space, 0)) {
01741       size_t new_size = (*pool_head)->size;
01742 
01743       while (new_size < to_alloc) {
01744          new_size *= 2;
01745       }
01746 
01747 #if defined(__AST_DEBUG_MALLOC)
01748       if (add_string_pool(mgr, pool_head, new_size, mgr->owner_file, mgr->owner_line, mgr->owner_func))
01749          return NULL;
01750 #else
01751       if (add_string_pool(mgr, pool_head, new_size, __FILE__, __LINE__, __FUNCTION__))
01752          return NULL;
01753 #endif
01754    }
01755 
01756    /* pool->base is always aligned (gcc aligned attribute). We ensure that
01757     * to_alloc is also a multiple of ast_alignof(ast_string_field_allocation)
01758     * causing result to always be aligned as well; which in turn fixes that
01759     * AST_STRING_FIELD_ALLOCATION(result) is aligned. */
01760    result = (*pool_head)->base + (*pool_head)->used;
01761    (*pool_head)->used += to_alloc;
01762    (*pool_head)->active += needed;
01763    result += ast_alignof(ast_string_field_allocation);
01764    AST_STRING_FIELD_ALLOCATION(result) = needed;
01765    mgr->last_alloc = result;
01766 
01767    return result;
01768 }

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 1662 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_mgr::owner_file, ast_string_field_mgr::owner_func, ast_string_field_mgr::owner_line, ast_string_field_pool::prev, and ast_string_field_pool::used.

01664 {
01665    const char **p = (const char **) pool_head + 1;
01666    struct ast_string_field_pool *cur = NULL;
01667    struct ast_string_field_pool *preserve = NULL;
01668 
01669    /* clear fields - this is always necessary */
01670    while ((struct ast_string_field_mgr *) p != mgr) {
01671       *p++ = __ast_string_field_empty;
01672    }
01673 
01674    mgr->last_alloc = NULL;
01675 #if defined(__AST_DEBUG_MALLOC)
01676    mgr->owner_file = file;
01677    mgr->owner_func = func;
01678    mgr->owner_line = lineno;
01679 #endif
01680    if (needed > 0) {    /* allocate the initial pool */
01681       *pool_head = NULL;
01682       mgr->embedded_pool = NULL;
01683       return add_string_pool(mgr, pool_head, needed, file, lineno, func);
01684    }
01685 
01686    /* if there is an embedded pool, we can't actually release *all*
01687     * pools, we must keep the embedded one. if the caller is about
01688     * to free the structure that contains the stringfield manager
01689     * and embedded pool anyway, it will be freed as part of that
01690     * operation.
01691     */
01692    if ((needed < 0) && mgr->embedded_pool) {
01693       needed = 0;
01694    }
01695 
01696    if (needed < 0) {    /* reset all pools */
01697       cur = *pool_head;
01698    } else if (mgr->embedded_pool) { /* preserve the embedded pool */
01699       preserve = mgr->embedded_pool;
01700       cur = *pool_head;
01701    } else {       /* preserve the last pool */
01702       if (*pool_head == NULL) {
01703          ast_log(LOG_WARNING, "trying to reset empty pool\n");
01704          return -1;
01705       }
01706       preserve = *pool_head;
01707       cur = preserve->prev;
01708    }
01709 
01710    if (preserve) {
01711       preserve->prev = NULL;
01712       preserve->used = preserve->active = 0;
01713    }
01714 
01715    while (cur) {
01716       struct ast_string_field_pool *prev = cur->prev;
01717 
01718       if (cur != preserve) {
01719          ast_free(cur);
01720       }
01721       cur = prev;
01722    }
01723 
01724    *pool_head = preserve;
01725 
01726    return 0;
01727 }

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 1873 of file utils.c.

References __ast_string_field_ptr_build_va().

01876 {
01877    va_list ap1, ap2;
01878 
01879    va_start(ap1, format);
01880    va_start(ap2, format);     /* va_copy does not exist on FreeBSD */
01881 
01882    __ast_string_field_ptr_build_va(mgr, pool_head, ptr, format, ap1, ap2);
01883 
01884    va_end(ap1);
01885    va_end(ap2);
01886 }

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 1813 of file utils.c.

References __ast_string_field_alloc_space(), __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().

01816 {
01817    size_t needed;
01818    size_t available;
01819    size_t space = (*pool_head)->size - (*pool_head)->used;
01820    ssize_t grow;
01821    char *target;
01822 
01823    /* if the field already has space allocated, try to reuse it;
01824       otherwise, try to use the empty space at the end of the current
01825       pool
01826    */
01827    if (*ptr != __ast_string_field_empty) {
01828       target = (char *) *ptr;
01829       available = AST_STRING_FIELD_ALLOCATION(*ptr);
01830       if (*ptr == mgr->last_alloc) {
01831          available += space;
01832       }
01833    } else {
01834       /* pool->used is always a multiple of ast_alignof(ast_string_field_allocation)
01835        * so we don't need to re-align anything here.
01836        */
01837       target = (*pool_head)->base + (*pool_head)->used + ast_alignof(ast_string_field_allocation);
01838       available = space - ast_alignof(ast_string_field_allocation);
01839    }
01840 
01841    needed = vsnprintf(target, available, format, ap1) + 1;
01842 
01843    if (needed > available) {
01844       /* the allocation could not be satisfied using the field's current allocation
01845          (if it has one), or the space available in the pool (if it does not). allocate
01846          space for it, adding a new string pool if necessary.
01847       */
01848       if (!(target = (char *) __ast_string_field_alloc_space(mgr, pool_head, needed))) {
01849          return;
01850       }
01851       vsprintf(target, format, ap2);
01852       __ast_string_field_release_active(*pool_head, *ptr);
01853       *ptr = target;
01854    } else if (*ptr != target) {
01855       /* the allocation was satisfied using available space in the pool, but not
01856          using the space already allocated to the field
01857       */
01858       __ast_string_field_release_active(*pool_head, *ptr);
01859       mgr->last_alloc = *ptr = target;
01860       AST_STRING_FIELD_ALLOCATION(target) = needed;
01861       (*pool_head)->used += ast_make_room_for(needed, ast_string_field_allocation);
01862       (*pool_head)->active += needed;
01863    } else if ((grow = (needed - AST_STRING_FIELD_ALLOCATION(*ptr))) > 0) {
01864       /* the allocation was satisfied by using available space in the pool *and*
01865          the field was the last allocated field from the pool, so it grew
01866       */
01867       AST_STRING_FIELD_ALLOCATION(*ptr) += grow;
01868       (*pool_head)->used += ast_align_for(grow, ast_string_field_allocation);
01869       (*pool_head)->active += grow;
01870    }
01871 }

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 1770 of file utils.c.

References AST_STRING_FIELD_ALLOCATION, and ast_string_field_mgr::last_alloc.

01773 {
01774    ssize_t grow = needed - AST_STRING_FIELD_ALLOCATION(*ptr);
01775    size_t space = (*pool_head)->size - (*pool_head)->used;
01776 
01777    if (*ptr != mgr->last_alloc) {
01778       return 1;
01779    }
01780 
01781    if (space < grow) {
01782       return 1;
01783    }
01784 
01785    (*pool_head)->used += grow;
01786    (*pool_head)->active += grow;
01787    AST_STRING_FIELD_ALLOCATION(*ptr) += grow;
01788 
01789    return 0;
01790 }

void __ast_string_field_release_active ( struct ast_string_field_pool pool_head,
const ast_string_field  ptr 
)

Definition at line 1792 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().

01794 {
01795    struct ast_string_field_pool *pool, *prev;
01796 
01797    if (ptr == __ast_string_field_empty) {
01798       return;
01799    }
01800 
01801    for (pool = pool_head, prev = NULL; pool; prev = pool, pool = pool->prev) {
01802       if ((ptr >= pool->base) && (ptr <= (pool->base + pool->size))) {
01803          pool->active -= AST_STRING_FIELD_ALLOCATION(ptr);
01804          if ((pool->active == 0) && prev) {
01805             prev->prev = pool->prev;
01806             ast_free(pool);
01807          }
01808          break;
01809       }
01810    }
01811 }


Variable Documentation

Definition at line 1607 of file utils.c.


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