Thu Apr 3 08:22:45 2014

Asterisk developer's documentation


stringfields.h File Reference

String fields in structures. More...

#include "asterisk/inline_api.h"
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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(), and sip_subscribe_mwi().

#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_localtag_registry(), 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__)
#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_register(), 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 1959 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.

01962 {
01963    struct ast_string_field_mgr *mgr;
01964    struct ast_string_field_pool *pool;
01965    struct ast_string_field_pool **pool_head;
01966    size_t pool_size_needed = sizeof(*pool) + pool_size;
01967    size_t size_to_alloc = optimal_alloc_size(struct_size + pool_size_needed);
01968    void *allocation;
01969    unsigned int x;
01970 
01971 #if defined(__AST_DEBUG_MALLOC)  
01972    if (!(allocation = __ast_calloc(num_structs, size_to_alloc, file, lineno, func))) {
01973       return NULL;
01974    }
01975 #else
01976    if (!(allocation = ast_calloc(num_structs, size_to_alloc))) {
01977       return NULL;
01978    }
01979 #endif
01980 
01981    for (x = 0; x < num_structs; x++) {
01982       void *base = allocation + (size_to_alloc * x);
01983       const char **p;
01984 
01985       mgr = base + field_mgr_offset;
01986       pool_head = base + field_mgr_pool_offset;
01987       pool = base + struct_size;
01988 
01989       p = (const char **) pool_head + 1;
01990       while ((struct ast_string_field_mgr *) p != mgr) {
01991          *p++ = __ast_string_field_empty;
01992       }
01993 
01994       mgr->embedded_pool = pool;
01995       *pool_head = pool;
01996       pool->size = size_to_alloc - struct_size - sizeof(*pool);
01997 #if defined(__AST_DEBUG_MALLOC)
01998       mgr->owner_file = file;
01999       mgr->owner_func = func;
02000       mgr->owner_line = lineno;
02001 #endif
02002    }
02003 
02004    return allocation;
02005 }

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 1800 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().

01802 {
01803    char *result = NULL;
01804    size_t space = (*pool_head)->size - (*pool_head)->used;
01805    size_t to_alloc;
01806 
01807    /* Make room for ast_string_field_allocation and make it a multiple of that. */
01808    to_alloc = ast_make_room_for(needed, ast_string_field_allocation);
01809    ast_assert(to_alloc % ast_alignof(ast_string_field_allocation) == 0);
01810 
01811    if (__builtin_expect(to_alloc > space, 0)) {
01812       size_t new_size = (*pool_head)->size;
01813 
01814       while (new_size < to_alloc) {
01815          new_size *= 2;
01816       }
01817 
01818 #if defined(__AST_DEBUG_MALLOC)
01819       if (add_string_pool(mgr, pool_head, new_size, mgr->owner_file, mgr->owner_line, mgr->owner_func))
01820          return NULL;
01821 #else
01822       if (add_string_pool(mgr, pool_head, new_size, __FILE__, __LINE__, __FUNCTION__))
01823          return NULL;
01824 #endif
01825    }
01826 
01827    /* pool->base is always aligned (gcc aligned attribute). We ensure that
01828     * to_alloc is also a multiple of ast_alignof(ast_string_field_allocation)
01829     * causing result to always be aligned as well; which in turn fixes that
01830     * AST_STRING_FIELD_ALLOCATION(result) is aligned. */
01831    result = (*pool_head)->base + (*pool_head)->used;
01832    (*pool_head)->used += to_alloc;
01833    (*pool_head)->active += needed;
01834    result += ast_alignof(ast_string_field_allocation);
01835    AST_STRING_FIELD_ALLOCATION(result) = needed;
01836    mgr->last_alloc = result;
01837 
01838    return result;
01839 }

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 1733 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.

01735 {
01736    const char **p = (const char **) pool_head + 1;
01737    struct ast_string_field_pool *cur = NULL;
01738    struct ast_string_field_pool *preserve = NULL;
01739 
01740    /* clear fields - this is always necessary */
01741    while ((struct ast_string_field_mgr *) p != mgr) {
01742       *p++ = __ast_string_field_empty;
01743    }
01744 
01745    mgr->last_alloc = NULL;
01746 #if defined(__AST_DEBUG_MALLOC)
01747    mgr->owner_file = file;
01748    mgr->owner_func = func;
01749    mgr->owner_line = lineno;
01750 #endif
01751    if (needed > 0) {    /* allocate the initial pool */
01752       *pool_head = NULL;
01753       mgr->embedded_pool = NULL;
01754       return add_string_pool(mgr, pool_head, needed, file, lineno, func);
01755    }
01756 
01757    /* if there is an embedded pool, we can't actually release *all*
01758     * pools, we must keep the embedded one. if the caller is about
01759     * to free the structure that contains the stringfield manager
01760     * and embedded pool anyway, it will be freed as part of that
01761     * operation.
01762     */
01763    if ((needed < 0) && mgr->embedded_pool) {
01764       needed = 0;
01765    }
01766 
01767    if (needed < 0) {    /* reset all pools */
01768       cur = *pool_head;
01769    } else if (mgr->embedded_pool) { /* preserve the embedded pool */
01770       preserve = mgr->embedded_pool;
01771       cur = *pool_head;
01772    } else {       /* preserve the last pool */
01773       if (*pool_head == NULL) {
01774          ast_log(LOG_WARNING, "trying to reset empty pool\n");
01775          return -1;
01776       }
01777       preserve = *pool_head;
01778       cur = preserve->prev;
01779    }
01780 
01781    if (preserve) {
01782       preserve->prev = NULL;
01783       preserve->used = preserve->active = 0;
01784    }
01785 
01786    while (cur) {
01787       struct ast_string_field_pool *prev = cur->prev;
01788 
01789       if (cur != preserve) {
01790          ast_free(cur);
01791       }
01792       cur = prev;
01793    }
01794 
01795    *pool_head = preserve;
01796 
01797    return 0;
01798 }

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 1944 of file utils.c.

References __ast_string_field_ptr_build_va().

01947 {
01948    va_list ap1, ap2;
01949 
01950    va_start(ap1, format);
01951    va_start(ap2, format);     /* va_copy does not exist on FreeBSD */
01952 
01953    __ast_string_field_ptr_build_va(mgr, pool_head, ptr, format, ap1, ap2);
01954 
01955    va_end(ap1);
01956    va_end(ap2);
01957 }

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 1884 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().

01887 {
01888    size_t needed;
01889    size_t available;
01890    size_t space = (*pool_head)->size - (*pool_head)->used;
01891    ssize_t grow;
01892    char *target;
01893 
01894    /* if the field already has space allocated, try to reuse it;
01895       otherwise, try to use the empty space at the end of the current
01896       pool
01897    */
01898    if (*ptr != __ast_string_field_empty) {
01899       target = (char *) *ptr;
01900       available = AST_STRING_FIELD_ALLOCATION(*ptr);
01901       if (*ptr == mgr->last_alloc) {
01902          available += space;
01903       }
01904    } else {
01905       /* pool->used is always a multiple of ast_alignof(ast_string_field_allocation)
01906        * so we don't need to re-align anything here.
01907        */
01908       target = (*pool_head)->base + (*pool_head)->used + ast_alignof(ast_string_field_allocation);
01909       available = space - ast_alignof(ast_string_field_allocation);
01910    }
01911 
01912    needed = vsnprintf(target, available, format, ap1) + 1;
01913 
01914    if (needed > available) {
01915       /* the allocation could not be satisfied using the field's current allocation
01916          (if it has one), or the space available in the pool (if it does not). allocate
01917          space for it, adding a new string pool if necessary.
01918       */
01919       if (!(target = (char *) __ast_string_field_alloc_space(mgr, pool_head, needed))) {
01920          return;
01921       }
01922       vsprintf(target, format, ap2);
01923       __ast_string_field_release_active(*pool_head, *ptr);
01924       *ptr = target;
01925    } else if (*ptr != target) {
01926       /* the allocation was satisfied using available space in the pool, but not
01927          using the space already allocated to the field
01928       */
01929       __ast_string_field_release_active(*pool_head, *ptr);
01930       mgr->last_alloc = *ptr = target;
01931       AST_STRING_FIELD_ALLOCATION(target) = needed;
01932       (*pool_head)->used += ast_make_room_for(needed, ast_string_field_allocation);
01933       (*pool_head)->active += needed;
01934    } else if ((grow = (needed - AST_STRING_FIELD_ALLOCATION(*ptr))) > 0) {
01935       /* the allocation was satisfied by using available space in the pool *and*
01936          the field was the last allocated field from the pool, so it grew
01937       */
01938       AST_STRING_FIELD_ALLOCATION(*ptr) += grow;
01939       (*pool_head)->used += ast_align_for(grow, ast_string_field_allocation);
01940       (*pool_head)->active += grow;
01941    }
01942 }

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 1841 of file utils.c.

References AST_STRING_FIELD_ALLOCATION, and ast_string_field_mgr::last_alloc.

01844 {
01845    ssize_t grow = needed - AST_STRING_FIELD_ALLOCATION(*ptr);
01846    size_t space = (*pool_head)->size - (*pool_head)->used;
01847 
01848    if (*ptr != mgr->last_alloc) {
01849       return 1;
01850    }
01851 
01852    if (space < grow) {
01853       return 1;
01854    }
01855 
01856    (*pool_head)->used += grow;
01857    (*pool_head)->active += grow;
01858    AST_STRING_FIELD_ALLOCATION(*ptr) += grow;
01859 
01860    return 0;
01861 }

void __ast_string_field_release_active ( struct ast_string_field_pool pool_head,
const ast_string_field  ptr 
)

Definition at line 1863 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().

01865 {
01866    struct ast_string_field_pool *pool, *prev;
01867 
01868    if (ptr == __ast_string_field_empty) {
01869       return;
01870    }
01871 
01872    for (pool = pool_head, prev = NULL; pool; prev = pool, pool = pool->prev) {
01873       if ((ptr >= pool->base) && (ptr <= (pool->base + pool->size))) {
01874          pool->active -= AST_STRING_FIELD_ALLOCATION(ptr);
01875          if ((pool->active == 0) && prev) {
01876             prev->prev = pool->prev;
01877             ast_free(pool);
01878          }
01879          break;
01880       }
01881    }
01882 }


Variable Documentation

Definition at line 1678 of file utils.c.


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