libwreport
2.4
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Implement fast access to information about WMO variables. More...
#include <stdint.h>
#include <string>
Go to the source code of this file.
Data Structures | |
struct | wreport::_Varinfo |
Holds the information about a DBALLE variable. More... | |
class | wreport::MutableVarinfo |
Smart pointer to handle/use varinfos. More... | |
class | wreport::Varinfo |
Smart pointer to handle/use varinfos. More... | |
Namespaces | |
namespace | wreport |
Main namespace. | |
Defines | |
#define | WR_VAR(f, x, y) ((wreport::Varcode)( ((unsigned)(f)<<14) | ((unsigned)(x)<<8) | (unsigned)(y) )) |
Create a WMO variable code from its F, X and Y components. | |
#define | WR_STRING_TO_VAR(str) |
Convert a XXYYY string to a WMO variable code. | |
#define | WR_VAR_F(code) (((code) >> 14) & 0x3) |
Get the F part of a WMO variable code. | |
#define | WR_VAR_X(code) ((code) >> 8 & 0x3f) |
Get the X part of a WMO variable code. | |
#define | WR_VAR_Y(code) ((code) & 0xff) |
Get the Y part of a WMO variable code. | |
#define | VARINFO_FLAG_STRING 0x01 |
Varinfo flags. | |
#define | VARINFO_FLAG_BINARY 0x02 |
Mark literal binary variables. | |
Typedefs | |
typedef short unsigned int | wreport::Varcode |
Holds the WMO variable code of a variable. | |
typedef short unsigned int | wreport::Alteration |
Describes how a wreport::Varinfo has been altered: it is used for supporting variables coming from BUFR and CREX messages that use C codes to alter variable information. | |
Functions | |
std::string | wreport::varcode_format (Varcode code) |
Format a varcode into a string. | |
Varcode | wreport::descriptor_code (const char *desc) |
Convert a FXXYYY string descriptor code into its short integer representation. |
Implement fast access to information about WMO variables.
The measured value of a physical quantity has little meaning without specifying what quantity it represents, what units are used to measure it, and how many digits are significant for the value.
This module provides access to all this metadata:
There are many B tables with slight differences used by different meteorological centre or equipment. This module allows to access different vartables using dba_vartable_create().
wreport::Vartable and wreport::Varinfo have special memory management: they are never deallocated. This is a precise design choice to speed up passing and copying wreport::Varinfo values, that are used very intensely as they accompany all the physical values processed by DB-All.e and its components. This behaviour should not be a cause of memory leaks, since a software would only need to access a limited amount of B tables during its lifetime.
To construct a wreport::Varcode value one needs to provide three numbers: F, X and Y.
The normal text representation of a wreport::Varcode for a WMO B table uses the format Bxxyyy.
#define VARINFO_FLAG_STRING 0x01 |
#define WR_STRING_TO_VAR | ( | str | ) |
((wreport::Varcode)( \ (( ((str)[0] - '0')*10 + ((str)[1] - '0') ) << 8) | \ ( ((str)[2] - '0')*100 + ((str)[3] - '0')*10 + ((str)[4] - '0') ) \ ))
Convert a XXYYY string to a WMO variable code.
This is useful only in rare cases, such as when parsing tables; use descriptor_code() to parse proper entry names such as "B01003" or "D21301".