Hashtable Delphi DLL Reference Documentation
Hashtable
Current Version: 11.0.0
Represents a collection of key/value pairs that are stored in a hash table.
Note: This class was added in Chilkat v9.5.0.51
Create/Dispose
var myObject: HCkHashtable; begin myObject := CkHashtable_Create(); // ... CkHashtable_Dispose(myObject); end;
Creates an instance of the HCkHashtable object and returns a handle (i.e. a Pointer). The handle is passed in the 1st argument for the functions listed on this page.
Objects created by calling CkHashtable_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function.
Properties
Count
The number of items (strings/integers) contained in the hash table.
topDebugLogFilePath
procedure CkHashtable_putDebugLogFilePath(objHandle: HCkHashtable; newPropVal: PWideChar); stdcall;
function CkHashtable__debugLogFilePath(objHandle: HCkHashtable): PWideChar; stdcall;
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
See the notes about PWideChar memory ownership and validity.
LastErrorHtml
function CkHashtable__lastErrorHtml(objHandle: HCkHashtable): PWideChar; stdcall;
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
See the notes about PWideChar memory ownership and validity.
topLastErrorText
function CkHashtable__lastErrorText(objHandle: HCkHashtable): PWideChar; stdcall;
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
See the notes about PWideChar memory ownership and validity.
LastErrorXml
function CkHashtable__lastErrorXml(objHandle: HCkHashtable): PWideChar; stdcall;
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
See the notes about PWideChar memory ownership and validity.
topLastMethodSuccess
procedure CkHashtable_putLastMethodSuccess(objHandle: HCkHashtable; newPropVal: wordbool); stdcall;
Indicates the success or failure of the most recent method call: True means success, False means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages.
VerboseLogging
procedure CkHashtable_putVerboseLogging(objHandle: HCkHashtable; newPropVal: wordbool); stdcall;
If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.
Version
function CkHashtable__version(objHandle: HCkHashtable): PWideChar; stdcall;
Version of the component/library, such as "10.1.0"
See the notes about PWideChar memory ownership and validity.
Methods
AddFromXmlSb
sbXml: HCkStringBuilder): wordbool; stdcall;
Adds to the hash table from XML previously created by calling ToXmlSb.
Returns True for success, False for failure.
AddInt
key: PWideChar;
value: Integer): wordbool; stdcall;
Adds or replaces an entry with the given key and integer value to the hash table. Returns True if a new hash entry was added or replaced. Returns False if an out-of-memory condition occurred.
Returns True for success, False for failure.
topAddQueryParams
queryParams: PWideChar): wordbool; stdcall;
Adds URL query parameters into the hashtable. The queryParams has the form: "field1=value1&field2=value2&field3=value3...". It is assumed that the values are URL encoded, and this method automatically URL decodes the values prior to inserting into the hashtable.
Returns True for success, False for failure.
AddStr
key: PWideChar;
value: PWideChar): wordbool; stdcall;
Adds or replaces an entry with the given key and string value to the hash table. Returns True if a new hash entry was added or replaced. Returns False if an out-of-memory condition occurred.
Returns True for success, False for failure.
topClear
Removes all elements from the Hashtable.
topClearWithNewCapacity
capacity: Integer): wordbool; stdcall;
Removes all elements from the Hashtable and re-sizes with the specified capacity.
The capacity is the number of buckets in the hash table. In the case of a "hash collision", a single bucket stores multiple entries, which must be searched sequentially. One rule of thumb is to set the capacity to twice the number of expected items to be hashed. It's also preferable to set the capacity to a prime number. (The 1st 10,000 prime numbers are listed here: https://primes.utm.edu/lists/small/10000.txt )
The initial default capacity of the hash table is 521.
Returns True for success, False for failure.
topContains
key: PWideChar): wordbool; stdcall;
Determines if a given key is contained within the hash table. Returns True if the key exists, otherwise returns False.
ContainsIntKey
key: Integer): wordbool; stdcall;
Determines if a given key is contained within the hash table. Returns True if the key exists, otherwise returns False.
GetKeys
Appends the complete set of hashtable key strings to strTable.
Returns True for success, False for failure.
LookupInt
key: PWideChar): Integer; stdcall;
Returns the integer value associated with the specified key. If the key is not in the hash table, the return value is 0.
topLookupStr
key: PWideChar;
outStr: HCkString): wordbool; stdcall;
function CkHashtable__lookupStr(objHandle: HCkHashtable;
key: PWideChar): PWideChar; stdcall;
Returns the string value associated with the specified key.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
topRemove
key: PWideChar): wordbool; stdcall;
Removes the entry with the specified key from the hash table. Returns True if the key existed and was removed. Returns False if the key did not already exist.
ToQueryString
outStr: HCkString): wordbool; stdcall;
function CkHashtable__toQueryString(objHandle: HCkHashtable): PWideChar; stdcall;
Serializes the hash table to a query string such as key1=value1&key2=value2&key3=value3 where each value is URL encoded.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
ToXmlSb
Serializes the hash table to XML format. The XML is appended to sbXml.
Returns True for success, False for failure.