BaseType Class Reference

The basic data type for the DODS DAP types. More...

#include <BaseType.h>

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List of all members.

Abstract Methods

virtual unsigned int buf2val (void **val)=0
 Reads the class data.
virtual bool deserialize (XDR *source, DDS *dds, bool reuse=false)=0
 Receive data from the net.
virtual void print_val (FILE *out, string space="", bool print_decl_p=true)=0
 Prints the value of the variable.
virtual bool serialize (const string &dataset, ConstraintEvaluator &eval, DDS &dds, XDR *sink, bool ce_eval=true)=0
 Move data to the net.
virtual unsigned int val2buf (void *val, bool reuse=false)=0
 Loads class data.
virtual unsigned int width ()=0
 Returns the size of the class instance data.

Public Member Functions

virtual void add_var (BaseType *bt, Part part=nil)
 Add a variable.
 BaseType (const BaseType &copy_from)
 The BaseType copy constructor.
 BaseType (const string &n="", const Type &t=dods_null_c, xdrproc_t xdr=NULL)
 The BaseType constructor.
virtual bool check_semantics (string &msg, bool all=false)
 Compare an object's current state with the semantics of its type.
virtual void dump (ostream &strm) const
 dumps information about this object
virtual int element_count (bool leaves=false)
 Count the members of constructor types.
virtual AttrTableget_attr_table ()
virtual BaseTypeget_parent ()
virtual bool is_constructor_type ()
 Returns true if the instance is a constructor (i.e., Structure, Sequence or Grid) type variable.
virtual bool is_in_selection ()
 Is this variable part of the current selection?
virtual bool is_simple_type ()
 Returns true if the instance is a numeric. string or URL type variable.
virtual bool is_vector_type ()
 Returns true if the instance is a vector (i.e., array) type variable.
string name () const
 Returns the name of the class instance.
BaseTypeoperator= (const BaseType &rhs)
virtual bool ops (BaseType *b, int op, const string &dataset)
 Evaluate relational operators.
virtual void print_decl (FILE *out, string space=" ", bool print_semi=true, bool constraint_info=false, bool constrained=false)
 Print an ASCII representation of the variable structure.
virtual void print_xml (FILE *out, string space=" ", bool constrained=false)
virtual BaseTypeptr_duplicate ()=0
virtual bool read (const string &dataset)
 Read data into a local buffer.
virtual bool read_p ()
 Has this variable been read?
virtual bool send_p ()
 Should this variable be sent?
virtual void set_attr_table (const AttrTable &at)
virtual void set_in_selection (bool state)
virtual void set_name (const string &n)
 Sets the name of the class instance.
virtual void set_parent (BaseType *parent)
virtual void set_read_p (bool state)
 Sets the value of the read_p property.
virtual void set_send_p (bool state)
virtual void set_synthesized_p (bool state)
void set_type (const Type &t)
 Sets the type of the class instance.
virtual bool synthesized_p ()
virtual string toString ()
Type type () const
 Returns the type of the class instance.
string type_name () const
 Returns the type of the class instance as a string.
virtual BaseTypevar (const string &name, btp_stack &s)
virtual BaseTypevar (const string &name="", bool exact_match=true, btp_stack *s=0)
 Returns a pointer to a member of a constructor class.
xdrproc_t xdr_coder ()
 Returns a function used to encode elements of an array.
virtual ~BaseType ()

Protected Member Functions

void _duplicate (const BaseType &bt)
 Perform a deep copy.

Detailed Description

This defines the basic data type features for the DODS data access protocol (DAP) data types. All the DAP type classes (Float64, Array, etc.) subclass it. This class is an abstract one; no variables will ever be stored as BaseType instances, only as instances of its child classes.

These classes and their methods give a user the capacity to set up sophisticated data types. They do not provide sophisticated ways to access and use this data. On the server side, in many cases, the class instances will have no data in them at all until the serialize function is called to send data to the client. On the client side, most DODS application programs will unpack the data promptly into whatever local data structure the programmer deems the most useful.

In order to use these classes on the server side of a DODS client/server connection, you must write a read method for each of the data types you expect to encounter in the application. This function, whose purpose is to read data from a local source into the class instance data buffer, is called in serialize, when the data is about to be sent to the client. The read function may be called earlier, in the case of data subset requests (constraint expressions) whose evaluation requires it. (For example, the constraint expression ``a,b&b>c'' requires that c be read even though it will not be sent.)

For some data types, the read function must be aware of the constraints to be returned. These cautions are outlined where they occur.

Todo:
We really need a better way to get values out of these types, esp. the Float32, Int16, ..., types. In most cases we know the type, so a type specific method (one that requires a downcast to use) is OK. For example, Byte might have a method dods_byte Byte::value(). Sure you have to downcast from BaseType to Byte in order to use it, but you have to figure out you have a Byte to use Byte::buf2val() anyway, so what's the big deal? Having a method that returns the value would simplify code that reads from data sets to extract meta data (like lat/lon corner points, et c.).

Definition at line 196 of file BaseType.h.


Constructor & Destructor Documentation

BaseType::BaseType ( const string &  n = "",
const Type t = dods_null_c,
xdrproc_t  xdr = NULL 
)

The BaseType constructor needs a name, a type, and the name of an XDR filter. The BaseType class exists to provide data to type classes that inherit from it. The constructors of those classes call the BaseType constructor; it is never called directly.

Note that the constructor (as well as the copy constructor via _duplicate) open/initialize the (XDRS *)s XDRIN and XDROUT to reference sdtin and stdout. This means that writing to std{in,out} must work correctly, and probably means that is must be OK to mix calls to cout/cin with calls that write to std{out,in} (it is for g++ with libg++ at version 2.6 or greater).

Parameters:
n A string containing the name of the new variable.
t The type of the variable.
xdr A pointer to an XDR filter to use to transmit the data in this variable to a client DODS process.
See also:
Type

Definition at line 101 of file BaseType.cc.

BaseType::BaseType ( const BaseType copy_from  ) 

Definition at line 107 of file BaseType.cc.

References _duplicate().

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BaseType::~BaseType (  )  [virtual]

Definition at line 112 of file BaseType.cc.

References DBG.


Member Function Documentation

void BaseType::_duplicate ( const BaseType bt  )  [protected]

Perform a deep copy. Copies the values of bt into *this. Pointers are dereferenced and their values are copied into a newly allocated instance.

Parameters:
bt The source object.

Definition at line 64 of file BaseType.cc.

References _name, _read_p, _send_p, _synthesized_p, _type, _xdr_coder, d_attr, d_in_selection, and d_parent.

Referenced by BaseType(), and operator=().

void BaseType::add_var ( BaseType bt,
Part  part = nil 
) [virtual]

Adds a variable to an instance of a constructor class, such as Array, Structure et cetera. This function is only used by those classes. For constructors with more than one variable, the variables appear in the same order in which they were added (i.e., the order in which add_var() was called). Since this method is only for use by Vectors and Constructors, the BaseType implementation throws InternalErr.

Note:
For the implementation of this method in Structure, Sequence, et c., first copy bt and then insert the copy. If bt is itself a constructor type you must either use the var() method to get a pointer to the actual instance added to *this or you must first add all of bt's children to it before adding it to *this. The implementations should use _duplicate() to perform a deep copy of bt.
Todo:
We should get rid of the Part parameter and adopt the convention that the first variable is the Array and all subsequent ones are Maps (when dealing with a Grid, the only time Part matters). This would enable several methods to migrate from Structure, Sequence and Grid to Constructor.
Parameters:
bt The variable to be added to this instance. The caller of this method must free memory it allocates for v. This method will make a deep copy of the object pointed to by v.
part The part of the constructor data to be modified. Only meaningful for Grid variables.
See also:
Part

Reimplemented in Array, Grid, Sequence, Structure, and Vector.

Definition at line 614 of file BaseType.cc.

Referenced by DDXParser::ddx_end_element().

virtual unsigned int BaseType::buf2val ( void **  val  )  [pure virtual]

Reads the class data into the memory referenced by val. The caller should either allocate enough storage to val to hold the class data or set *val to null. If *val is NULL, memory will be allocated by this function with new(). If the memory is allocated this way, the caller is responsible for deallocating that memory. Array and values for simple types are stored as C would store an array.

Parameters:
val A pointer to a pointer to the memory into which the class data will be copied. If the value pointed to is NULL, memory will be allocated to hold the data, and the pointer value modified accordingly. The calling program is responsible for deallocating the memory references by this pointer.
Returns:
The size (in bytes) of the information copied to val.

Implemented in Byte, Float32, Float64, Grid, Int16, Int32, Sequence, Str, Structure, UInt16, UInt32, and Vector.

Referenced by libdap::extract_double_value(), and libdap::extract_string_argument().

bool BaseType::check_semantics ( string &  msg,
bool  all = false 
) [virtual]

This function checks the class instance for internal consistency. This is important to check for complex constructor classes. For BaseType, an object is semantically correct if it has both a non-null name and type.

For example, an Int32 instance would return FALSE if it had no name or no type defined. A Grid instance might return FALSE for more complex reasons, such as having Map arrays of the wrong size or shape.

This function is used by the DDS class, and will rarely, if ever, be explicitly called by a DODS application program. A variable must pass this test before it is sent, but there may be many other stages in a retrieve operation where it would fail.

Returns:
Returns FALSE when the current state violates some aspect of the type semantics, TRUE otherwise.
Parameters:
msg A returned string, containing a message indicating the source of any problem.
all For complex constructor types (Grid, Sequence, Structure), this flag indicates whether to check the semantics of the member variables, too.
See also:
DDS::check_semantics

Reimplemented in Array, Grid, Sequence, Structure, and Vector.

Definition at line 851 of file BaseType.cc.

References dods_null_c.

Referenced by Vector::check_semantics(), Structure::check_semantics(), Sequence::check_semantics(), Grid::check_semantics(), and Array::check_semantics().

virtual bool BaseType::deserialize ( XDR *  source,
DDS dds,
bool  reuse = false 
) [pure virtual]

Receives data from the network connection identified by the source parameter. The data is put into the class data buffer according to the input dds.

This function is only used on the client side of the DODS client/server connection.

Parameters:
source A valid XDR pointer to the process connection to the net. This is generally created with a call to new_xdrstdio().
dds The Data Descriptor Structure object corresponding to this dataset. See The DODS User Manual for information about this structure. This would have been received from the server in an earlier transmission.
reuse A boolean value, indicating whether the class internal data storage can be reused or not. If this argument is TRUE, the class buffer is assumed to be large enough to hold the incoming data, and it is not reallocated. If FALSE, new storage is allocated. If the internal buffer has not been allocated at all, this argument has no effect.
Returns:
Always returns TRUE.
Exceptions:
Error when a problem reading from the XDR stream is found.
See also:
DDS

Implemented in Byte, Float32, Float64, Grid, Int16, Int32, Sequence, Str, Structure, UInt16, UInt32, and Vector.

Referenced by Grid::deserialize().

void BaseType::dump ( ostream &  strm  )  const [virtual]

Displays the pointer value of this instance and then displays information about this base type.

Parameters:
strm C++ i/o stream to dump the information to
Returns:
void

Implements DapObj.

Reimplemented in Array, Byte, Constructor, Float32, Float64, Grid, Int16, Int32, Sequence, Str, Structure, UInt16, UInt32, and Vector.

Definition at line 158 of file BaseType.cc.

References AttrTable::dump(), DapIndent::Indent(), DapIndent::LMarg(), type_name(), and DapIndent::UnIndent().

Referenced by Vector::dump(), UInt32::dump(), UInt16::dump(), Str::dump(), Int32::dump(), Int16::dump(), Grid::dump(), Float64::dump(), Float32::dump(), Constructor::dump(), and Byte::dump().

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int BaseType::element_count ( bool  leaves = false  )  [virtual]

Return a count of the total number of variables in this variable. This is used to count the number of variables held by a constructor variable - for simple type and vector variables it always returns 1.

For compound data types, there are two ways to count members. You can count the members, or you can count the simple members and add that to the count of the compound members. For example, if a Structure contains an Int32 and another Structure that itself contains two Int32 members, the element count of the top-level structure could be two (one Int32 and one Structure) or three (one Int32 by itself and two Int32's in the subsidiary Structure). Use the leaves parameter to control which kind of counting you desire.

Returns:
Returns 1 for simple types. For compound members, the count depends on the leaves argument.
Parameters:
leaves This parameter is only relevant if the object contains other compound data types. If FALSE, the function counts only the data variables mentioned in the object's declaration. If TRUE, it counts the simple members, and adds that to the sum of the counts for the compound members. This parameter has no effect for simple type variables.

Reimplemented in Grid, Sequence, Structure, and Vector.

Definition at line 358 of file BaseType.cc.

Referenced by Vector::element_count().

AttrTable & BaseType::get_attr_table (  )  [virtual]

Get this variable's AttrTable. It's generally a bad idea to return a reference to a contained object, but in this case it seems that building an interface inside BaseType is overkill.

Use the AttrTable methods to manipulate the table.

Definition at line 480 of file BaseType.cc.

Referenced by DDS::find_matching_container(), Constructor::find_matching_container(), Grid::print_xml(), Constructor::print_xml(), print_xml(), and Array::print_xml_core().

BaseType * BaseType::get_parent (  )  [virtual]

Return a pointer to the Constructor or Vector which holds (contains) this variable. If this variable is at the top level, this method returns null.

Returns:
A BaseType pointer to the variable's parent.

Definition at line 550 of file BaseType.cc.

Referenced by DDS::find_matching_container(), Constructor::find_matching_container(), libdap::function_linear_scale(), Sequence::serialize_leaf(), Sequence::serialize_parent_part_two(), Sequence::transfer_data_for_leaf(), and Sequence::transfer_data_parent_part_two().

bool BaseType::is_constructor_type (  )  [virtual]

Definition at line 307 of file BaseType.cc.

References dods_array_c, dods_byte_c, dods_float32_c, dods_float64_c, dods_grid_c, dods_int16_c, dods_int32_c, dods_null_c, dods_sequence_c, dods_str_c, dods_structure_c, dods_uint16_c, dods_uint32_c, dods_url_c, and type().

Referenced by DDXParser::ddx_end_element(), DDS::transfer_attributes(), Constructor::transfer_attributes(), and Vector::var().

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bool BaseType::is_in_selection (  )  [virtual]

Does this variable appear in either the selection part or as a function argument in the current constrain expression. If this property is set (true) then implementations of the read() method should read this variable.

Note:
This method does not check, nor does it know about the semantics of, string arguments passed to functions. Those functions might include variable names in strings; they are responsible for reading those variables. See the grid (func_grid_select()) for an example.
See also:
BaseType::read()

Definition at line 505 of file BaseType.cc.

bool BaseType::is_simple_type (  )  [virtual]

Definition at line 250 of file BaseType.cc.

References dods_array_c, dods_byte_c, dods_float32_c, dods_float64_c, dods_grid_c, dods_int16_c, dods_int32_c, dods_null_c, dods_sequence_c, dods_str_c, dods_structure_c, dods_uint16_c, dods_uint32_c, dods_url_c, and type().

Referenced by Grid::check_semantics(), libdap::extract_double_array(), libdap::extract_double_value(), and libdap::set_array_using_double().

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bool BaseType::is_vector_type (  )  [virtual]

Definition at line 277 of file BaseType.cc.

References dods_array_c, dods_byte_c, dods_float32_c, dods_float64_c, dods_grid_c, dods_int16_c, dods_int32_c, dods_null_c, dods_sequence_c, dods_str_c, dods_structure_c, dods_uint16_c, dods_uint32_c, dods_url_c, and type().

Referenced by DDXParser::ddx_end_element().

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string BaseType::name (  )  const

Definition at line 181 of file BaseType.cc.

Referenced by Structure::_duplicate(), Vector::add_var(), Structure::check_semantics(), Sequence::check_semantics(), Grid::check_semantics(), Sequence::deserialize(), DDS::exact_match(), libdap::extract_double_array(), libdap::function_linear_scale(), GSEClause::get_map_name(), GridGeoConstraint::GridGeoConstraint(), GSEClause::GSEClause(), DDS::mark(), Grid::print_decl(), Constructor::print_decl(), Grid::print_xml(), Constructor::print_xml(), Array::print_xml_core(), Sequence::read_row(), Sequence::serialize(), Sequence::serialize_leaf(), Sequence::serialize_parent_part_one(), Sequence::serialize_parent_part_two(), Sequence::set_leaf_sequence(), set_name(), set_read_p(), Constructor::transfer_attributes(), Sequence::transfer_data(), Sequence::transfer_data_for_leaf(), Sequence::transfer_data_parent_part_one(), Sequence::transfer_data_parent_part_two(), Sequence::transfer_data_private(), rvalue::value_name(), Vector::var(), Structure::var(), Sequence::var(), and Grid::var().

BaseType & BaseType::operator= ( const BaseType rhs  ) 

Definition at line 119 of file BaseType.cc.

References _duplicate().

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bool BaseType::ops ( BaseType b,
int  op,
const string &  dataset 
) [virtual]

This method contains the relational operators used by the constraint expression evaluator in the DDS class. Each class that wants to be able to evaluate relational expressions must overload this function. The implementation in BaseType throws an InternalErr exception. The DAP library classes Byte, ..., Url provide specializations of this method. It is not meaningful for classes such as Array because relational expressions using Array are not supported.

The op argument refers to a table generated by bison from the constraint expression parser. Use statements like the following to correctly interpret its value:

    switch (op) {
        case EQUAL: return i1 == i2;
        case NOT_EQUAL: return i1 != i2;
        case GREATER: return i1 > i2;
        case GREATER_EQL: return i1 >= i2;
        case LESS: return i1 < i2;
        case LESS_EQL: return i1 <= i2;
        case REGEXP: throw Error("Regular expressions are not supported for integer values");
        default: throw Error("Unknown operator");
    }
    

This function is used by the constraint expression evaluator.

Parameters:
b Compare the value of this instance with b.
op An integer index indicating which relational operator is implied. Choose one from the following: EQUAL, NOT_EQUAL, GREATER, GREATER_EQL, LESS, LESS_EQL, and REGEXP.
dataset The name of the dataset from which the instance's data has come (or is to come).
Returns:
The boolean value of the comparison.

Reimplemented in Byte, Float32, Float64, Int16, Int32, Str, UInt16, and UInt32.

Definition at line 898 of file BaseType.cc.

Referenced by Clause::value().

void BaseType::print_decl ( FILE *  out,
string  space = "    ",
bool  print_semi = true,
bool  constraint_info = false,
bool  constrained = false 
) [virtual]

Write the variable's declaration in a C-style syntax. This function is used to create textual representation of the Data Descriptor Structure (DDS). See The DODS User Manual for information about this structure.

A simple array declaration might look like this:

    Float64 lat[lat = 180];
    
While a more complex declaration (for a Grid, in this case), would look like this:
    Grid {
    ARRAY:
    Int32 sst[time = 404][lat = 180][lon = 360];
    MAPS:
    Float64 time[time = 404];
    Float64 lat[lat = 180];
    Float64 lon[lon = 360];
    } sst;
    

Parameters:
out The output stream on which to print the declaration.
space Each line of the declaration will begin with the characters in this string. Usually used for leading spaces.
print_semi A boolean value indicating whether to print a semicolon at the end of the declaration.
constraint_info A boolean value indicating whether constraint information is to be printed with the declaration. If the value of this parameter is TRUE, print_decl() prints the value of the variable's send_p() flag after the declaration.
constrained If this boolean value is TRUE, the variable's declaration is only printed if is the send_p() flag is TRUE. If a constraint expression is in place, and this variable is not requested, the send_p() flag is FALSE.
See also:
DDS

DDS::CE

Reimplemented in Array, Constructor, and Grid.

Definition at line 762 of file BaseType.cc.

References id2www(), send_p(), and type_name().

Referenced by DODSFilter::functional_constraint(), Grid::print_decl(), Array::print_decl(), UInt32::print_val(), UInt16::print_val(), Str::print_val(), Int32::print_val(), Int16::print_val(), Float64::print_val(), Float32::print_val(), and Byte::print_val().

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virtual void BaseType::print_val ( FILE *  out,
string  space = "",
bool  print_decl_p = true 
) [pure virtual]

Prints the value of the variable, with its declaration. This function is primarily intended for debugging DODS applications. However, it can be overloaded and used to do some useful things. Take a look at the asciival and writeval clients, both of which overload this to output the values of variables in different ways.

Parameters:
out The output FILE on which to print the value.
space This value is passed to the print_decl() function, and controls the leading spaces of the output.
print_decl_p A boolean value controlling whether the variable declaration is printed as well as the value.

Implemented in Array, Byte, Float32, Float64, Grid, Int16, Int32, Sequence, Str, Structure, UInt16, and UInt32.

Referenced by Sequence::print_one_row(), and Grid::print_val().

void BaseType::print_xml ( FILE *  out,
string  space = "    ",
bool  constrained = false 
) [virtual]

Write the XML representation of this variable. This method is used to build the DDX XML response.

Parameters:
out Destination.
space Use this to indent child declarations. Default is "".
constrained If true, only print this if it's part part of the current projection. Default is False.

Reimplemented in Array, Constructor, and Grid.

Definition at line 791 of file BaseType.cc.

References get_attr_table(), id2xml(), AttrTable::print_xml(), send_p(), and type_name().

Referenced by Array::print_xml_core().

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virtual BaseType* BaseType::ptr_duplicate (  )  [pure virtual]

Clone this instance. Allocate a new instance and copy *this into it. This method must perform a deep copy.

Note:
This method should not copy data values, but must copy all other fields in the object.
Returns:
A newly allocated copy of this.

Implemented in Array, Byte, Float32, Float64, Grid, Int16, Int32, PassiveArray, PassiveByte, PassiveFloat32, PassiveFloat64, PassiveInt16, PassiveInt32, PassiveStr, PassiveStructure, PassiveUInt16, PassiveUInt32, PassiveUrl, Sequence, Str, Structure, UInt16, UInt32, Url, and Vector.

Referenced by Vector::_duplicate(), Vector::add_var(), Structure::add_var(), Sequence::add_var(), Grid::add_var(), DDS::add_var(), Vector::deserialize(), libdap::function_geoarray(), libdap::function_geogrid(), and Vector::set_vec().

bool BaseType::read ( const string &  dataset  )  [virtual]

This method should be implemented for each of the data type classes (Byte, ..., Grid) when using the DAP class library to build a server. This method is only for DAP servers. The library provides a default definition here which throws an InternalErr exception unless the read_p property has been set. In that case it returns false, indicating that all the data have been read. The latter case can happen when building a constant value that needs to be passed to a function. The variable/constant is loaded with a value when it is created.

When implementing a new DAP server, the Byte, ..., Grid data type classes are usually specialized. In each of those specializations read() should be defined to read values from the data source and store them in the object's local buffer. The read() method is called by other methods in this library. When writing read(), follow these rules:

Returns:
The return value of this method for all types except Sequence should always be false. Sequences should return true to indicate more values remain in the Sequence, false to indicate no more values remain. (see Sequence::serialize() and Sequence::read_row()).
Parameters:
dataset A string naming the dataset from which the data is to be read. The meaning of this string will vary among different types of data sources. It may be the name of a data file or an identifier used to read data from a relational database.
See also:
BaseType

Sequence

Reimplemented in PassiveArray, PassiveByte, PassiveFloat32, PassiveFloat64, PassiveInt16, PassiveInt32, PassiveStr, PassiveStructure, PassiveUInt16, and PassiveUInt32.

Definition at line 690 of file BaseType.cc.

Referenced by GridGeoConstraint::apply_constraint_to_data(), ArrayGeoConstraint::apply_constraint_to_data(), libdap::function_geogrid(), libdap::function_grid(), libdap::function_linear_scale(), UInt32::ops(), UInt16::ops(), Str::ops(), Int32::ops(), Int16::ops(), Float64::ops(), Float32::ops(), Byte::ops(), Sequence::read_row(), GeoConstraint::reorder_data_longitude_axis(), Vector::serialize(), UInt32::serialize(), UInt16::serialize(), Structure::serialize(), Str::serialize(), Int32::serialize(), Int16::serialize(), Grid::serialize(), Float64::serialize(), Float32::serialize(), Byte::serialize(), and Structure::transfer_data().

bool BaseType::read_p (  )  [virtual]

Returns true if the value(s) for this variable have been read from the data source, otherwise returns false. This method is used to determine when values need to be read using the read() method. When read_p() returns true, this library assumes that buf2val() (and other methods such as get_vec()) can be used to access the value(s) of a variable.

Returns:
True if the variable's value(s) have been read, false otherwise.

Definition at line 395 of file BaseType.cc.

Referenced by libdap::extract_double_array(), libdap::extract_double_value(), libdap::extract_string_argument(), UInt32::ops(), UInt16::ops(), Str::ops(), Int32::ops(), Int16::ops(), Float64::ops(), Float32::ops(), Byte::ops(), PassiveUInt32::read(), PassiveUInt16::read(), PassiveStr::read(), PassiveInt32::read(), PassiveInt16::read(), PassiveFloat64::read(), PassiveFloat32::read(), PassiveByte::read(), PassiveArray::read(), Sequence::read_row(), Vector::serialize(), UInt32::serialize(), UInt16::serialize(), Structure::serialize(), Str::serialize(), Int32::serialize(), Int16::serialize(), Grid::serialize(), Float64::serialize(), Float32::serialize(), Byte::serialize(), and Structure::transfer_data().

bool BaseType::send_p (  )  [virtual]

Returns the state of the send_p property. If true, this variable should be sent to the client, if false, it should not. If no constraint expression (CE) has been evaluated, this property is true for all variables in a data source (i.e., for all the variables listed in a DDS). If a CE has been evaluated, this property is true only for those variables listed in the projection part of the CE.

Returns:
True if the variable should be sent to the client, false otherwise.

Definition at line 453 of file BaseType.cc.

Referenced by Grid::components(), Grid::print_decl(), Constructor::print_decl(), print_decl(), Array::print_decl(), Grid::print_val(), Grid::print_xml(), Constructor::print_xml(), print_xml(), Array::print_xml_core(), Grid::projection_yields_grid(), and Grid::serialize().

virtual bool BaseType::serialize ( const string &  dataset,
ConstraintEvaluator eval,
DDS dds,
XDR *  sink,
bool  ce_eval = true 
) [pure virtual]

Sends the data from the indicated (local) dataset through the connection identified by the sink parameter. If the data is not already incorporated into the DDS object, read the data from the dataset.

This function is only used on the server side of the client/server connection, and is generally only called from the DODSFilter::send() function. It has no BaseType implementation; each datatype child class supplies its own implementation.

Parameters:
dataset The (local) name of dataset to be read.
eval Use this as the constraint expression evaluator.
dds The Data Descriptor Structure object corresponding to this dataset. See The DODS User Manual for information about this structure.
sink A valid XDR pointer generally created with a call to new_xdrstdio(). This typically routes data to a TCP/IP socket.
ce_eval A boolean value indicating whether to evaluate the DODS constraint expression that may accompany this dataset. The constraint expression is stored in dds.
Returns:
This method always returns true. Older versions used the return value to signal success or failure.
Exceptions:
InternalErr. 
Error. 
See also:
DDS

Implemented in Byte, Float32, Float64, Grid, Int16, Int32, Sequence, Str, Structure, UInt16, UInt32, and Vector.

Referenced by DODSFilter::functional_constraint(), and Grid::serialize().

void BaseType::set_attr_table ( const AttrTable at  )  [virtual]

Set this variable's attribute table.

Parameters:
at Source of the attributes.

Definition at line 488 of file BaseType.cc.

void BaseType::set_in_selection ( bool  state  )  [virtual]

Set the in_selection property to state. This property indicates that the variable is used as a parameter to a constraint expression function or that it appears as an argument in a selection sub-expression. If set (true), implementations of the BaseType::read() method should read this variable.

Parameters:
state Set the in_selection property to this state.
See also:
BaseType::read()

BaseType::is_in_selection() for more information.

Reimplemented in Grid, Sequence, and Structure.

Definition at line 520 of file BaseType.cc.

Referenced by Structure::set_in_selection(), Sequence::set_in_selection(), and Grid::set_in_selection().

void BaseType::set_name ( const string &  n  )  [virtual]

Definition at line 188 of file BaseType.cc.

References name(), and www2id().

Referenced by Vector::add_var(), and Array::print_xml_core().

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void BaseType::set_parent ( BaseType parent  )  [virtual]

Set the parent property for this variable. Only instances of Constructor or Vector should call this method.

Parameters:
parent Pointer to the Constructor of Vector parent variable.
Exceptions:
InternalErr thrown if called with anything other than a Constructor or Vector.

Definition at line 533 of file BaseType.cc.

Referenced by Vector::_duplicate(), Structure::_duplicate(), Vector::add_var(), Structure::add_var(), Sequence::add_var(), Grid::add_var(), and Vector::Vector().

void BaseType::set_read_p ( bool  state  )  [virtual]

Sets the value of the read_p property. This indicates that the value(s) of this variable has/have been read. An implementation of the read() method would typically use this to set the read_p property to true.

Note:
For most of the types the default implementation of this method is fine. However, if you're building a server which must handle data represented using nested sequences, then you may need to provide a specialization of Sequence::set_read_p(). By default Sequence::set_read_() recursively sets the read_p property for all child variables to state. For servers where one Sequence reads an outer set of values and another reads an inner set, this is cumbersome. In such a case, it is easier to specialize Sequence::set_read_p() so that it does not recursively set the read_p property for the inner Sequence. Be sure to see the documentation for the read() method!

For synthesized variables, this method does nothing. Thus, if a synthesized variable is added to a Sequence, the Sequence can iteratively reset the read_p property without affecting the value of that property for the synthesized variable. That's important since a synthesized variable's value is calculated, not read.

Todo:
Look at making synthesized variables easier to implement and at making them more integrated into the overall CE evaluation process. Maybe the code that computes the synthesized var's value should be in the that variable's read() method? This might provide a way to get rid of the awkward 'projection functions' by replacing them with real children of BaseType. It would also provide a way to clean up the way the synthesized_p prop intrudes on the read_p prop.
See also:
BaseType::read()
Parameters:
state Set the read_p property to this state.

Reimplemented in Grid, Sequence, Structure, and Vector.

Definition at line 434 of file BaseType.cc.

References DBG, and name().

Referenced by PassiveUInt32::read(), PassiveUInt16::read(), PassiveStr::read(), PassiveInt32::read(), PassiveInt16::read(), PassiveFloat64::read(), PassiveFloat32::read(), PassiveByte::read(), Vector::set_read_p(), Structure::set_read_p(), Sequence::set_read_p(), Grid::set_read_p(), UInt32::set_value(), UInt16::set_value(), Str::set_value(), Int32::set_value(), Int16::set_value(), Float64::set_value(), Float32::set_value(), and Byte::set_value().

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void BaseType::set_send_p ( bool  state  )  [virtual]

Sets the value of the send_p flag. This function is meant to be called from serialize(). Data is ready to be sent when both the _send_p and _read_p flags are set to TRUE.

Parameters:
state The logical state to set the send_p flag.

Reimplemented in Grid, Sequence, Structure, and Vector.

Definition at line 466 of file BaseType.cc.

References DBG.

Referenced by DDS::mark(), Vector::set_send_p(), Structure::set_send_p(), Sequence::set_send_p(), and Grid::set_send_p().

void BaseType::set_synthesized_p ( bool  state  )  [virtual]

Set the synthesized flag. Before setting this flag be sure to set the read_p() state. Once this flag is set you cannot alter the state of the read_p flag!

See also:
synthesized_p()

Definition at line 378 of file BaseType.cc.

void BaseType::set_type ( const Type t  ) 

Definition at line 203 of file BaseType.cc.

Referenced by Url::Url().

bool BaseType::synthesized_p (  )  [virtual]

Returns true if the variable is a synthesized variable. A synthesized variable is one that is added to the dataset by the server (usually with a `projection function'.

Definition at line 367 of file BaseType.cc.

string BaseType::toString (  )  [virtual]

Write out the object's internal fields in a string. To be used for debugging when regular inspection w/ddd or gdb isn't enough.

Returns:
A string which shows the object's internal stuff.

Reimplemented in Sequence.

Definition at line 134 of file BaseType.cc.

References type_name().

Referenced by Sequence::add_var(), GSEClause::GSEClause(), and Sequence::toString().

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Type BaseType::type (  )  const

Definition at line 196 of file BaseType.cc.

Referenced by Array::add_var(), Vector::buf2val(), Grid::check_semantics(), Vector::deserialize(), libdap::extract_double_array(), libdap::extract_double_value(), libdap::extract_string_argument(), DDS::find_matching_container(), Constructor::find_matching_container(), libdap::function_linear_scale(), is_constructor_type(), is_simple_type(), is_vector_type(), UInt32::ops(), UInt16::ops(), Str::ops(), Int32::ops(), Int16::ops(), Float64::ops(), Float32::ops(), Byte::ops(), Sequence::print_one_row(), PassiveArray::read(), Vector::serialize(), Sequence::serialize_leaf(), Sequence::serialize_parent_part_two(), libdap::set_array_using_double(), Vector::set_value(), PassiveArray::set_value(), Vector::set_vec(), Sequence::transfer_data_for_leaf(), Sequence::transfer_data_parent_part_two(), Vector::val2buf(), Vector::value(), and Vector::var().

string BaseType::type_name (  )  const

Definition at line 210 of file BaseType.cc.

References dods_array_c, dods_byte_c, dods_float32_c, dods_float64_c, dods_grid_c, dods_int16_c, dods_int32_c, dods_null_c, dods_sequence_c, dods_str_c, dods_structure_c, dods_uint16_c, dods_uint32_c, and dods_url_c.

Referenced by Vector::add_var(), Structure::check_semantics(), Sequence::check_semantics(), Grid::check_semantics(), Vector::deserialize(), dump(), Grid::print_decl(), Constructor::print_decl(), print_decl(), Constructor::print_xml(), print_xml(), and toString().

virtual unsigned int BaseType::val2buf ( void *  val,
bool  reuse = false 
) [pure virtual]

Store the value pointed to by val in the object's internal buffer. This function does not perform any checks, so users must be sure that the thing pointed to can actually be stored in the object's buffer.

Only simple objects (Int, Float, Byte, and so on) and arrays of these simple objects may be stored using this function. To put data into more complex constructor types, use the functions provided by that class.

Parameters:
val A pointer to the data to be inserted into the class data buffer.
reuse A boolean value, indicating whether the class internal data storage can be reused or not. If this argument is TRUE, the class buffer is assumed to be large enough to hold the incoming data, and it is not reallocated. If FALSE, new storage is allocated. If the internal buffer has not been allocated at all, this argument has no effect. This is currently used only in the Vector class.
Returns:
The size (in bytes) of the information copied from val.
See also:
Grid

Vector::val2buf

Implemented in Byte, Float32, Float64, Grid, Int16, Int32, Sequence, Str, Structure, UInt16, UInt32, and Vector.

Referenced by libdap::function_linear_scale(), and Vector::var().

BaseType * BaseType::var ( const string &  name,
btp_stack s 
) [virtual]

This version of var(...) searches for name and returns a pointer to the BaseType object if found. It uses the same search algorithm as BaseType::var(const string &, bool, btp_stack *) when exact_match is false. In addition to returning a pointer to the variable, it pushes onto s a BaseType pointer to each constructor type that ultimately contains name.

Note:
The BaseType implementation always returns null. There are no default values for the parameters. If var() is called w/o any params, the three parameter version will be used.
Deprecated:
This method is deprecated because it tries first to use exact_match and, if that fails, then tries leaf_match. It's better to use the alternate form of var(...) and specify exactly what you'd like to do.
Returns:
A pointer to the named variable.

Reimplemented in Grid, Sequence, Structure, and Vector.

Definition at line 579 of file BaseType.cc.

BaseType * BaseType::var ( const string &  name = "",
bool  exact_match = true,
btp_stack s = 0 
) [virtual]

Returns a pointer to the contained variable in a composite class. The composite classes are those made up of aggregated simple data types. Array, Grid, and Structure are composite types, while Int and Float are simple types. This function is only used by composite classes. The BaseType implementation always returns null.

Several of the subclasses provide alternate access methods that make sense for that particular data type. For example, the Array class defines a *var(int i) method that returns the ith entry in the Array data, and the Structure provides a *var(Vars_iter) function using a pseudo-index to access the different members of the structure.

Parameters:
name The name of the class member. Defaults to ""
exact_match True if only interested in variables whose full names match n exactly. If false, returns the first variable whose name matches name. For example, if name is x and point.x is a variable, then var("x", false) would return a BaseType pointer to point.x. If exact_match was true then name would need to be "point.x" for var to return that pointer. This feature simplifies constraint expressions for datasets which have complex, nested, constructor variables. Defaults to true.
s Record the path to name. Defaults to null, in which case it is not used.
Returns:
A pointer to the member named in the n argument. If no name is given, the function returns the first (only) variable. For example, an Array has only one variable, while a Structure can have many.

Reimplemented in Grid, Sequence, Structure, and Vector.

Definition at line 557 of file BaseType.cc.

Referenced by DDS::exact_match(), Constructor::find_matching_container(), and Vector::var().

virtual unsigned int BaseType::width (  )  [pure virtual]

Return the number of bytes that are required to hold the instance's value. In the case of simple types such as Int32, this is the size of one Int32 (four bytes). For a String or Url type, width() returns the number of bytes needed for a String * variable, not the bytes needed for all the characters, since that value cannot be determined from type information alone. For Structure, and other constructor types size() returns the number of bytes needed to store pointers to the C++ objects.

Implemented in Byte, Float32, Float64, Grid, Int16, Int32, Sequence, Str, Structure, UInt16, UInt32, and Vector.

Referenced by Vector::deserialize(), GeoConstraint::reorder_data_longitude_axis(), Vector::serialize(), Vector::var(), Vector::width(), and Grid::width().

xdrproc_t BaseType::xdr_coder (  ) 

The xdr_coder function (also "filter primitive") is used to encode and decode each element in a multiple element data structure. These functions are used to convert data to and from its local representation to the XDR representation, which is used to transmit and receive the data. See man xdr for more information about the available XDR filter primitives.

Note that this class data is only used for multiple element data types. The simple data types (Int, Float, and so on), are translated directly.

Returns:
A C function used to encode data in the XDR format.

Definition at line 713 of file BaseType.cc.

Referenced by Vector::deserialize(), and Vector::serialize().


The documentation for this class was generated from the following files:
Generated on Wed Jun 27 12:57:34 2007 for libdap++ by  doxygen 1.4.7