libdap++ Updated for version 3.8.2
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#include <DDS.h>
Public Types | |
typedef std::vector< BaseType * > ::const_iterator | Vars_citer |
typedef std::vector< BaseType * > ::iterator | Vars_iter |
typedef std::vector< BaseType * > ::reverse_iterator | Vars_riter |
Public Member Functions | |
void | add_var (BaseType *bt) |
Adds a copy of the variable to the DDS. Using the ptr_duplicate() method, perform a deep copy on the variable bt and adds the result to this DDS. | |
bool | check_semantics (bool all=false) |
Check the semantics of each of the variables represented in the DDS. | |
DDS (const DDS &dds) | |
DDS (BaseTypeFactory *factory, const string &n="") | |
void | del_var (const string &n) |
Removes a variable from the DDS. | |
void | del_var (Vars_iter i) |
Removes a variable from the DDS. | |
void | del_var (Vars_iter i1, Vars_iter i2) |
Removes a range of variables from the DDS. | |
virtual void | dump (ostream &strm) const |
dumps information about this object | |
virtual AttrTable & | get_attr_table () |
int | get_dap_major () const |
Get the DAP major version as sent by the client. | |
int | get_dap_minor () const |
Get the DAP minor version as sent by the client. | |
BaseTypeFactory * | get_factory () const |
string | get_request_xml_base () const |
Get the URL that will return this DDS/DDX/DataThing. | |
int | get_timeout () |
BaseType * | get_var_index (int i) |
Get a variable. | |
Vars_iter | get_vars_iter (int i) |
Get an iterator. | |
bool | mark (const string &name, bool state) |
Mark the send_p flag of the named variable to state. | |
void | mark_all (bool state) |
int | num_var () |
Returns the number of variables in the DDS. | |
DDS & | operator= (const DDS &rhs) |
void | parse (int fd) |
Parse a DDS from a file indicated by the input file descriptor. | |
void | parse (FILE *in=stdin) |
Parse a DDS from a file indicated by the input file descriptor. Read the persistent representation of a DDS from the FILE *in, parse it and create a matching binary object. | |
void | parse (string fname) |
Parse a DDS from a file with the given name. | |
void | print (ostream &out) |
Print the entire DDS to the specified ostream. | |
void | print_constrained (ostream &out) |
Print a constrained DDS to the specified ostream. | |
void | print_xml (ostream &out, bool constrained, const string &blob="") |
void | set_dap_major (int p) |
Set the DAP major version (typically using info from the client) | |
void | set_dap_minor (int p) |
Set the DAP minor version (typically using info from the client) | |
void | set_dap_version (const string &version_string) |
BaseTypeFactory * | set_factory (BaseTypeFactory *factory) |
void | set_request_xml_base (const string &xb) |
void | set_timeout (int t) |
void | tag_nested_sequences () |
Traverse DDS, set Sequence leaf nodes. | |
void | timeout_off () |
void | timeout_on () |
virtual void | transfer_attributes (DAS *das) |
BaseType * | var (const string &n, BaseType::btp_stack *s=0) |
Find the variable with the given name. | |
BaseType * | var (const string &n, BaseType::btp_stack &s) |
Vars_iter | var_begin () |
Return an iterator to the first variable. | |
Vars_iter | var_end () |
Return an iterator. | |
Vars_riter | var_rbegin () |
Return a reverse iterator. | |
Vars_riter | var_rend () |
Return a reverse iterator. | |
virtual | ~DDS () |
Dataset Name Accessors | |
Get and set the dataset's name. This is the name of the dataset itself, and is not to be confused with the name of the file or disk on which it is stored. | |
string | get_dataset_name () const |
void | set_dataset_name (const string &n) |
File Name Accessor | |
Get and set the dataset's filename. This is the physical location on a disk where the dataset exists. The dataset name is simply a title.
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string | filename () |
void | filename (const string &fn) |
Container Name Accessor | |
Get and set the current container. If there are multiple files being used to build this DDS, using a container will set a virtual structure for the current container.
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string | container_name () |
void | container_name (const string &cn) |
Structure * | container () |
Protected Member Functions | |
void | duplicate (const DDS &dds) |
BaseType * | exact_match (const string &name, BaseType::btp_stack *s=0) |
BaseType * | leaf_match (const string &name, BaseType::btp_stack *s=0) |
Friends | |
class | DDSTest |
The DAP2 Data Descriptor Object (DDS) is a data structure used by the DAP2 software to describe datasets and subsets of those datasets. The DDS may be thought of as the declarations for the data structures that will hold data requested by some DAP2 client. Part of the job of a DAP2 server is to build a suitable DDS for a specific dataset and to send it to the client. Depending on the data access API in use, this may involve reading part of the dataset and inferring the DDS. Other APIs may require the server simply to read some ancillary data file with the DDS in it.
On the server side, in addition to the data declarations, the DDS holds the clauses of any constraint expression that may have accompanied the data request from the DAP2 client. The DDS object includes methods for modifying the DDS according to the given constraint expression. It also has methods for directly modifying a DDS, and for transmitting it from a server to a client.
For the client, the DDS object includes methods for reading the persistent form of the object sent from a server. This includes parsing the ASCII representation of the object and, possibly, reading data received from a server into a data object.
Note that the class DDS is used to instantiate both DDS and DataDDS objects. A DDS that is empty (contains no actual data) is used by servers to send structural information to the client. The same DDS can becomes a DataDDS when data values are bound to the variables it defines.
For a complete description of the DDS layout and protocol, please refer to The OPeNDAP User Guide.
The DDS has an ASCII representation, which is what is transmitted from a DAP2 server to a client. Here is the DDS representation of an entire dataset containing a time series of worldwide grids of sea surface temperatures:
Dataset { Float64 lat[lat = 180]; Float64 lon[lon = 360]; Float64 time[time = 404]; Grid { ARRAY: Int32 sst[time = 404][lat = 180][lon = 360]; MAPS: Float64 time[time = 404]; Float64 lat[lat = 180]; Float64 lon[lon = 360]; } sst; } weekly;
If the data request to this dataset includes a constraint expression, the corresponding DDS might be different. For example, if the request was only for northern hemisphere data at a specific time, the above DDS might be modified to appear like this:
Dataset { Grid { ARRAY: Int32 sst[time = 1][lat = 90][lon = 360]; MAPS: Float64 time[time = 1]; Float64 lat[lat = 90]; Float64 lon[lon = 360]; } sst; } weekly;
Since the constraint has narrowed the area of interest, the range of latitude values has been halved, and there is only one time value in the returned array. Note that the simple arrays (lat
, lon
, and time
) described in the dataset are also part of the sst
Grid object. They can be requested by themselves or as part of that larger object.
See the The OPeNDAP User Guide, or the documentation of the BaseType class for descriptions of the DAP2 data types.
typedef std::vector<BaseType *>::const_iterator libdap::DDS::Vars_citer |
typedef std::vector<BaseType *>::iterator libdap::DDS::Vars_iter |
typedef std::vector<BaseType *>::reverse_iterator libdap::DDS::Vars_riter |
libdap::DDS::DDS | ( | BaseTypeFactory * | factory, |
const string & | n = "" |
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) |
Make a DDS which uses the given BaseTypeFactory to create variables.
n | The name of the dataset. Can also be set using the set_dataset_name() method. |
factory | BaseTypeFactory which instantiates Byte, ..., Grid. The caller is responsible for freeing the object after deleting this DDS. Can also be set using set_factory(). Never delete until just before deleting the DDS itself unless you intend to replace the factory with a new instance. |
n | The name of the data set. Can also be set using set_dataset_name(). |
Definition at line 142 of file DDS.cc.
References DBG.
libdap::DDS::DDS | ( | const DDS & | rhs | ) |
The DDS copy constructor.
Definition at line 153 of file DDS.cc.
References DBG, and duplicate().
void libdap::DDS::add_var | ( | BaseType * | bt | ) |
bt | Source variable. |
Definition at line 572 of file DDS.cc.
References libdap::Structure::add_var(), DBG2, and libdap::BaseType::ptr_duplicate().
Referenced by container_name(), libdap::DDXParser::ddx_end_document(), and libdap::ConstraintEvaluator::eval_function_clauses().
bool libdap::DDS::check_semantics | ( | bool | all = false | ) |
Check the semantics of the DDS describing a complete dataset. If ALL is true, check not only the semantics of THIS->TABLE, but also recursively all ctor types in the THIS->TABLE. By default, ALL is false since parsing a DDS input file runs semantic checks on all variables (but not the dataset itself.
all | If true, recursively check the individual members of compound variables. |
Definition at line 1208 of file DDS.cc.
References libdap::unique_names().
Structure * libdap::DDS::container | ( | ) |
string libdap::DDS::container_name | ( | ) |
void libdap::DDS::container_name | ( | const string & | cn | ) |
void libdap::DDS::del_var | ( | Vars_iter | i | ) |
void libdap::DDS::del_var | ( | const string & | n | ) |
Remove the named variable from the DDS. This method is not smart about looking up names. The variable must exist at the top level of the DDS and must match exactly the name given.
n | The name of the variable to remove. |
Definition at line 603 of file DDS.cc.
References libdap::Structure::del_var().
void libdap::DDS::dump | ( | ostream & | strm | ) | const [virtual] |
Displays the pointer value of this instance and then calls parent dump
strm | C++ i/o stream to dump the information to |
Implements libdap::DapObj.
Reimplemented in libdap::DataDDS.
Definition at line 1312 of file DDS.cc.
References libdap::AttrTable::dump(), libdap::DapIndent::Indent(), libdap::DapIndent::LMarg(), and libdap::DapIndent::UnIndent().
void libdap::DDS::duplicate | ( | const DDS & | dds | ) | [protected] |
Definition at line 110 of file DDS.cc.
References DBG, var_begin(), and var_end().
Referenced by DDS(), and operator=().
BaseType * libdap::DDS::exact_match | ( | const string & | name, |
BaseType::btp_stack * | s = 0 |
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) | [protected] |
Definition at line 733 of file DDS.cc.
References DBG2, libdap::BaseType::name(), libdap::BaseType::var(), and var().
Referenced by var().
void libdap::DDS::filename | ( | const string & | fn | ) |
AttrTable & libdap::DDS::get_attr_table | ( | ) | [virtual] |
Get the attribute table for the global attributes.
Definition at line 460 of file DDS.cc.
Referenced by libdap::DDXParser::ddx_start_document().
int libdap::DDS::get_dap_major | ( | ) | const [inline] |
Definition at line 254 of file DDS.h.
Referenced by print_xml().
int libdap::DDS::get_dap_minor | ( | ) | const [inline] |
Definition at line 256 of file DDS.h.
Referenced by print_xml().
string libdap::DDS::get_dataset_name | ( | ) | const |
Returns the dataset's name.
Definition at line 444 of file DDS.cc.
Referenced by libdap::ConstraintEvaluator::eval_function_clauses().
BaseTypeFactory* libdap::DDS::get_factory | ( | ) | const [inline] |
Return the factory which makes instances of the Byte, ..., Grid type classes. Specialize BaseTypeFactory so that a DDS will be populated with your client or server's specialized types.
Definition at line 230 of file DDS.h.
Referenced by libdap::ConstraintEvaluator::eval_function_clauses(), libdap::Connect::request_ddx(), and libdap::Connect::request_ddx_url().
string libdap::DDS::get_request_xml_base | ( | ) | const [inline] |
Definition at line 266 of file DDS.h.
Referenced by print_xml().
BaseType * libdap::DDS::get_var_index | ( | int | i | ) |
DDS::Vars_iter libdap::DDS::get_vars_iter | ( | int | i | ) |
BaseType * libdap::DDS::leaf_match | ( | const string & | name, |
BaseType::btp_stack * | s = 0 |
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) | [protected] |
Definition at line 697 of file DDS.cc.
References DBG, libdap::BaseType::is_constructor_type(), libdap::BaseType::is_vector_type(), libdap::BaseType::name(), and libdap::BaseType::var().
Referenced by var().
bool libdap::DDS::mark | ( | const string & | n, |
bool | state | ||
) |
Mark the named variable by setting its SEND_P flag to STATE (true indicates that it is to be sent). Names must be fully qualified.
Definition at line 1254 of file DDS.cc.
References DBG2, libdap::BaseType::name(), libdap::BaseType::set_send_p(), libdap::BaseType::type_name(), and var().
void libdap::DDS::mark_all | ( | bool | state | ) |
Definition at line 170 of file DDS.cc.
References DBG, and duplicate().
void libdap::DDS::parse | ( | string | fname | ) |
Definition at line 858 of file DDS.cc.
References cannot_read_file.
Referenced by parse(), libdap::Ancillary::read_ancillary_dds(), libdap::Connect::request_dds(), and libdap::Connect::request_dds_url().
void libdap::DDS::parse | ( | int | fd | ) |
void libdap::DDS::parse | ( | FILE * | in = stdin | ) |
in | Read the persistent DDS from this FILE*. |
InternalErr | Thrown if in is null |
Error | Thrown if the parse fails. |
Definition at line 908 of file DDS.cc.
References DBG2, dds_buffer(), dds_delete_buffer(), dds_switch_to_buffer(), and ddsparse().
void libdap::DDS::print | ( | ostream & | out | ) |
Definition at line 959 of file DDS.cc.
References libdap::id2www().
Referenced by main(), and libdap::DODSFilter::send_dds().
void libdap::DDS::print_constrained | ( | ostream & | out | ) |
Print those parts (variables) of the DDS structure to OS that are marked to be sent after evaluating the constraint expression.
Definition at line 1012 of file DDS.cc.
References libdap::id2www().
Referenced by libdap::DODSFilter::dataset_constraint(), and libdap::DODSFilter::send_dds().
void libdap::DDS::print_xml | ( | ostream & | out, |
bool | constrained, | ||
const string & | blob = "" |
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) |
Print an XML representation of this DDS. This method is used to generate the part of the DDX response. The Dataset
tag is not written by this code. The caller of this method must handle writing that and including the dataBLOB
tag.
out | Destination ostream. |
constrained | True if the output should be limited to just those variables that are in the projection of the current constraint expression. |
blob | The dataBLOB href. |
Definition at line 1130 of file DDS.cc.
References c_dap20_namespace, c_dap32_namespace, c_default_dap20_schema_location, c_default_dap32_schema_location, c_xml_namespace, get_dap_major(), get_dap_minor(), get_request_xml_base(), grddl_transformation_dap32, libdap::id2xml(), libdap::AttrTable::print_xml(), var_begin(), and var_end().
Referenced by libdap::DODSFilter::dataset_constraint_ddx(), main(), and libdap::DODSFilter::send_ddx().
void libdap::DDS::set_dap_major | ( | int | p | ) | [inline] |
Definition at line 259 of file DDS.h.
Referenced by set_dap_version().
void libdap::DDS::set_dap_minor | ( | int | p | ) | [inline] |
Definition at line 261 of file DDS.h.
Referenced by set_dap_version().
void libdap::DDS::set_dap_version | ( | const string & | version_string | ) |
Given the dap protocol version either from a MIME header or from within the DDX Dataset element, parse that string and set the DDS fields.
version_string | The version string from the MIME of XML document. |
Definition at line 494 of file DDS.cc.
References DBG, set_dap_major(), and set_dap_minor().
Referenced by libdap::DDXParser::ddx_sax2_start_element().
void libdap::DDS::set_dataset_name | ( | const string & | n | ) |
Sets the dataset name.
Definition at line 451 of file DDS.cc.
Referenced by libdap::DDXParser::ddx_sax2_start_element().
BaseTypeFactory* libdap::DDS::set_factory | ( | BaseTypeFactory * | factory | ) | [inline] |
void libdap::DDS::set_request_xml_base | ( | const string & | xb | ) | [inline] |
void libdap::DDS::set_timeout | ( | int | t | ) |
Definition at line 831 of file DDS.cc.
Referenced by libdap::DODSFilter::send_data(), and libdap::DODSFilter::send_data_ddx().
void libdap::DDS::tag_nested_sequences | ( | ) |
Definition at line 846 of file DDS.cc.
References libdap::dods_sequence_c, and libdap::dods_structure_c.
Referenced by libdap::DODSFilter::send_data(), and libdap::DODSFilter::send_data_ddx().
void libdap::DDS::timeout_off | ( | ) |
Definition at line 823 of file DDS.cc.
Referenced by libdap::Grid::intern_data(), libdap::BaseType::intern_data(), libdap::Sequence::read_row(), libdap::Vector::serialize(), libdap::UInt32::serialize(), libdap::UInt16::serialize(), libdap::Structure::serialize(), libdap::Str::serialize(), libdap::Int32::serialize(), libdap::Int16::serialize(), libdap::Grid::serialize(), libdap::Float64::serialize(), libdap::Float32::serialize(), and libdap::Byte::serialize().
void libdap::DDS::timeout_on | ( | ) |
Definition at line 815 of file DDS.cc.
Referenced by libdap::Grid::intern_data(), libdap::BaseType::intern_data(), libdap::Sequence::read_row(), libdap::Vector::serialize(), libdap::UInt32::serialize(), libdap::UInt16::serialize(), libdap::Structure::serialize(), libdap::Str::serialize(), libdap::Int32::serialize(), libdap::Int16::serialize(), libdap::Grid::serialize(), libdap::Float64::serialize(), libdap::Float32::serialize(), and libdap::Byte::serialize().
void libdap::DDS::transfer_attributes | ( | DAS * | das | ) | [virtual] |
This is the main method used to transfer attributes from a DAS object into a DDS. This uses the BaseType::transfer_attributes() method and the various implementations found here (in the constructors classes) and in handlers.
This method uses a deep copy to transfer the attributes, to it's safe to delete the source DAS object passed to this method once it's done.
das | Transfer (copy) attributes from this DAS object. |
Definition at line 367 of file DDS.cc.
References libdap::AttrTable::append_container(), libdap::AttrTable::attr_begin(), libdap::Attr_container, libdap::AttrTable::attr_end(), libdap::DAS::container_name(), DBG, libdap::AttrTable::get_name(), libdap::DAS::get_top_level_attributes(), var(), var_begin(), and var_end().
Referenced by main().
BaseType * libdap::DDS::var | ( | const string & | n, |
BaseType::btp_stack & | s | ||
) |
Search for for variable n as above but record all compound type variables which ultimately contain n on s. This stack can then be used to mark the contained compound-type variables as part of the current projection.
Definition at line 659 of file DDS.cc.
Referenced by container_name(), exact_match(), mark(), and transfer_attributes().
BaseType * libdap::DDS::var | ( | const string & | n, |
BaseType::btp_stack * | s = 0 |
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) |
Returns a pointer to the named variable. If the name contains one or more field separators then the function looks for a variable whose name matches exactly. If the name contains no field separators then the function looks first in the top level and then in all subsequent levels and returns the first occurrence found. In general, this function searches constructor types in the order in which they appear in the DDS, but there is no requirement that it do so.
n | The name of the variable to find. |
s | If given, this value-result parameter holds the path to the returned BaseType. Thus, this method can return the FQN for the variable n. |
Definition at line 683 of file DDS.cc.
References exact_match(), leaf_match(), libdap::Structure::var(), and libdap::www2id().
DDS::Vars_iter libdap::DDS::var_begin | ( | ) |
Returns the first variable in the DDS.
Definition at line 766 of file DDS.cc.
Referenced by libdap::DODSFilter::dataset_constraint(), libdap::DODSFilter::dataset_constraint_ddx(), duplicate(), print_xml(), and transfer_attributes().
DDS::Vars_iter libdap::DDS::var_end | ( | ) |
Definition at line 778 of file DDS.cc.
Referenced by libdap::DODSFilter::dataset_constraint(), libdap::DODSFilter::dataset_constraint_ddx(), duplicate(), print_xml(), and transfer_attributes().
DDS::Vars_riter libdap::DDS::var_rbegin | ( | ) |
DDS::Vars_riter libdap::DDS::var_rend | ( | ) |