diff options
| author | Joey Adams | 2010-08-05 22:33:38 +0000 |
|---|---|---|
| committer | Joey Adams | 2010-08-05 22:33:38 +0000 |
| commit | c713ff84a84722381619769d7f15d99591eb23ae (patch) | |
| tree | cf659e1e415c6e9afd64a048e810c27a8e485c2f | |
| parent | e2aa55c3495632acae227967dc850e20748796e5 (diff) | |
Simplified and documented getTypeInfo.
Also touched up documentation for FN_EXTRA a bit.
| -rw-r--r-- | json_io.c | 13 | ||||
| -rw-r--r-- | util.c | 43 | ||||
| -rw-r--r-- | util.h | 40 |
3 files changed, 51 insertions, 45 deletions
@@ -200,13 +200,15 @@ to_json(PG_FUNCTION_ARGS) json_type target_type; typeInfo = FN_EXTRA(); - if (!typeInfo) + if (typeInfo == NULL) { typeInfo = FN_EXTRA_ALLOC(sizeof(TypeInfo)); - initTypeInfo(typeInfo, FN_MCXT()); + getTypeInfo(typeInfo, argtype, IOFunc_output, FN_MCXT()); + } + else if (typeInfo->type != argtype) + { + getTypeInfo(typeInfo, argtype, IOFunc_output, FN_MCXT()); } - - getTypeInfo(typeInfo, argtype, IOFunc_output); target_type = decide_json_type(argtype, typeInfo->typcategory); @@ -352,8 +354,7 @@ array_to_json(Datum datum) * computing now) in the fcinfo->flinfo->fn_mcxt of to_json like we do * with the TypeInfo of the array itself. */ - initTypeInfo(&element_typeinfo, CurrentMemoryContext); - getTypeInfo(&element_typeinfo, element_type, IOFunc_output); + getTypeInfo(&element_typeinfo, element_type, IOFunc_output, CurrentMemoryContext); target_type = decide_json_type(element_type, element_typeinfo.typcategory); @@ -15,30 +15,35 @@ #include "mb/pg_wchar.h" #include "utils/syscache.h" +/* + * getTypeInfo + * Retrieve information about a type, along with either its + * input, output, binary receive, or binary send procedure. + * + * which_func should be one of: + * IOFunc_input + * IOFunc_output + * IOFunc_receive + * IOFunc_send + * + * mcxt is the memory context the IO function selected will use to store + * subsidiary data. The memory context should live at least as long as + * the TypeInfo structure you specify. + */ void -initTypeInfo(TypeInfo *d, MemoryContext mcxt) +getTypeInfo(TypeInfo *d, Oid type, IOFuncSelector which_func, MemoryContext mcxt) { + d->type = type; + d->which_func = which_func; d->mcxt = mcxt; - d->not_set = true; -} -void -getTypeInfo(TypeInfo *d, Oid type, IOFuncSelector which_func) -{ - if (d->not_set || d->type != type || d->which_func != which_func) - { - get_type_io_data(type, which_func, - &d->typlen, &d->typbyval, &d->typalign, - &d->typdelim, &d->typioparam, &d->typiofunc); - fmgr_info_cxt(d->typiofunc, &d->proc, d->mcxt); + get_type_io_data(type, which_func, + &d->typlen, &d->typbyval, &d->typalign, + &d->typdelim, &d->typioparam, &d->typiofunc); + fmgr_info_cxt(d->typiofunc, &d->proc, d->mcxt); - get_type_category_preferred(type, - &d->typcategory, &d->typispreferred); - - d->type = type; - d->which_func = which_func; - d->not_set = false; - } + get_type_category_preferred(type, + &d->typcategory, &d->typispreferred); } Oid @@ -18,26 +18,29 @@ #include "utils/lsyscache.h" /* - * Macros for manipulating context preserved across function calls. + * FN_EXTRA, FN_EXTRA_ALLOC, FN_MCXT + * Macros for manipulating context preserved across function calls. * - * FN_EXTRA is primarily used for caching lookups across - * multiple calls of a function. + * FN_EXTRA is typically used for caching lookups and other nontrivial + * operations across multiple calls of a user-defined function. * - * Typical usage looks like: + * Do not use FN_EXTRA in a set-returning function. Use user_fctx instead. * - * my_extra = FN_EXTRA(); - * if (!my_extra) - * { - * my_extra = FN_EXTRA_ALLOC(sizeof(MyExtra)); - * my_extra->type_name = NULL; - * } + * Typical usage looks like: * - * if (my_extra->type_name == NULL || - * strcmp(my_extra->type_name, type_name) != 0) - * { - * my_extra->type_name = MemoryContextStrdup(FN_MCXT(), type_name); - * my_extra->type_id = TypenameGetTypid(my_extra->type_name); - * } + * my_extra = FN_EXTRA(); + * if (my_extra == NULL) + * { + * my_extra = FN_EXTRA_ALLOC(sizeof(MyExtra)); + * my_extra->type_name = NULL; + * } + * + * if (my_extra->type_name == NULL || + * strcmp(my_extra->type_name, type_name) != 0) + * { + * my_extra->type_name = MemoryContextStrdup(FN_MCXT(), type_name); + * my_extra->type_id = TypenameGetTypid(my_extra->type_name); + * } */ #define FN_EXTRA() (fcinfo->flinfo->fn_extra) #define FN_EXTRA_ALLOC(size) \ @@ -55,8 +58,6 @@ typedef struct IOFuncSelector which_func; MemoryContext mcxt; - bool not_set; - int16 typlen; bool typbyval; char typalign; @@ -69,8 +70,7 @@ typedef struct bool typispreferred; } TypeInfo; -void initTypeInfo(TypeInfo *d, MemoryContext mcxt); -void getTypeInfo(TypeInfo *d, Oid type, IOFuncSelector which_func); +void getTypeInfo(TypeInfo *d, Oid type, IOFuncSelector which_func, MemoryContext mcxt); Oid enumLabelToOid(const char *typname, const char *label); |