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endurox:v8.0.x:api:ubf:cbvget.3
Name
CBvget — Get and convert to user type data from VIEW buffer field
Synopsis
#include <ubf.h>
int CBvget(char *cstruct, char *view, char *cname, BFLDOCC occ, char *buf, BFLDLEN *len, int usrtype, long flags);
Link with -lubf -lnstd -lm -lpthread
DESCRIPTION
Function is used to get field data dynamically from VIEW buffer. cstruct is pointer to C structure instance (object), view is name of the VIEW (must match the instance of the object), occ is field array occurrence, if field is not an array or first array element must be read, then use occ=0. buf is buffer where to output the data. len is used on both directions, on input it is used for indicating the length of the bytes for the target buffer (buf). If the data is larger than len indicated, then error BNOSPACE is returned. Then len is optional. If set to NULL, then no such checks are made, and it is assumed that buffer length is sufficient to store the data. len is used only for BFLD_STRING and BFLD_CARRAY fields. On output len (if not NULL), indicates the length of data loaded in buf. Indicated in bytes. usrtype is user type indicating the data type of the buf, if types are different, the automatic data conversion is performed. flags is either set to 0 in which case data is returned as is in the VIEW, does not matter if it matches the NULL value specified in VIEW file or not, the exact value is returned. If flag BVACCESS_NOTNULL is specified, then if value in field matches NULL column in view file, then error BNOTPRES is returned. BNOTPRES can be returned in case if C flag was set in view file, and the count indicator is set to less than occurrence specified.
RETURN VALUE
On success, CBvget() return zero; on error, -1 is returned, with Berror set to indicate the error.
ERRORS
Note that Bstrerror() returns generic error message plus custom message with debug info from last function call, stored in thread local storage (TLS).
BEINVAL view, cstruct or buf is NULL. view or cname is empty string (first byte 0x00). Or occurrence is out of bounds of the array declaration.
BBADVIEW invalid view name (not found in view file).
BNOCNAME field name (cname) not found in view structure.
BNOSPACE No space in buf.
BMALLOC Failed to allocate type conversion buffer.
BNOTPRES Field not present (in case field value matches NULL in view file and BVACCESS_NOTNULL is set or count (C_) field is less than occurrence requested.