le_cfg_interface.h File Reference

#include "legato.h"

Go to the source code of this file.

Macros

#define LE_CFG_STR_LEN   511
 
#define LE_CFG_STR_LEN_BYTES   512
 
#define LE_CFG_NAME_LEN   127
 
#define LE_CFG_NAME_LEN_BYTES   128
 

Typedefs

typedef void(* le_cfg_DisconnectHandler_t) (void *)
 
typedef struct le_cfg_Iterator * le_cfg_IteratorRef_t
 
typedef struct le_cfg_ChangeHandler * le_cfg_ChangeHandlerRef_t
 
typedef void(* le_cfg_ChangeHandlerFunc_t) (void *contextPtr)
 

Enumerations

enum  le_cfg_nodeType_t {
  LE_CFG_TYPE_EMPTY = 0, LE_CFG_TYPE_STRING = 1, LE_CFG_TYPE_BOOL = 2, LE_CFG_TYPE_INT = 3,
  LE_CFG_TYPE_FLOAT = 4, LE_CFG_TYPE_STEM = 5, LE_CFG_TYPE_DOESNT_EXIST = 6
}
 

Functions

void le_cfg_ConnectService (void)
 
le_result_t le_cfg_TryConnectService (void)
 
void le_cfg_SetServerDisconnectHandler (le_cfg_DisconnectHandler_t disconnectHandler, void *contextPtr)
 
void le_cfg_DisconnectService (void)
 
le_cfg_IteratorRef_t le_cfg_CreateReadTxn (const char *basePath)
 
le_cfg_IteratorRef_t le_cfg_CreateWriteTxn (const char *basePath)
 
void le_cfg_CommitTxn (le_cfg_IteratorRef_t iteratorRef)
 
void le_cfg_CancelTxn (le_cfg_IteratorRef_t iteratorRef)
 
void le_cfg_GoToNode (le_cfg_IteratorRef_t iteratorRef, const char *newPath)
 
le_result_t le_cfg_GoToParent (le_cfg_IteratorRef_t iteratorRef)
 
le_result_t le_cfg_GoToFirstChild (le_cfg_IteratorRef_t iteratorRef)
 
le_result_t le_cfg_GoToNextSibling (le_cfg_IteratorRef_t iteratorRef)
 
le_result_t le_cfg_GetPath (le_cfg_IteratorRef_t iteratorRef, const char *path, char *pathBuffer, size_t pathBufferSize)
 
le_cfg_nodeType_t le_cfg_GetNodeType (le_cfg_IteratorRef_t iteratorRef, const char *path)
 
le_result_t le_cfg_GetNodeName (le_cfg_IteratorRef_t iteratorRef, const char *path, char *name, size_t nameSize)
 
le_cfg_ChangeHandlerRef_t le_cfg_AddChangeHandler (const char *newPath, le_cfg_ChangeHandlerFunc_t handlerPtr, void *contextPtr)
 
void le_cfg_RemoveChangeHandler (le_cfg_ChangeHandlerRef_t handlerRef)
 
void le_cfg_DeleteNode (le_cfg_IteratorRef_t iteratorRef, const char *path)
 
bool le_cfg_IsEmpty (le_cfg_IteratorRef_t iteratorRef, const char *path)
 
void le_cfg_SetEmpty (le_cfg_IteratorRef_t iteratorRef, const char *path)
 
bool le_cfg_NodeExists (le_cfg_IteratorRef_t iteratorRef, const char *path)
 
le_result_t le_cfg_GetString (le_cfg_IteratorRef_t iteratorRef, const char *path, char *value, size_t valueSize, const char *defaultValue)
 
void le_cfg_SetString (le_cfg_IteratorRef_t iteratorRef, const char *path, const char *value)
 
int32_t le_cfg_GetInt (le_cfg_IteratorRef_t iteratorRef, const char *path, int32_t defaultValue)
 
void le_cfg_SetInt (le_cfg_IteratorRef_t iteratorRef, const char *path, int32_t value)
 
double le_cfg_GetFloat (le_cfg_IteratorRef_t iteratorRef, const char *path, double defaultValue)
 
void le_cfg_SetFloat (le_cfg_IteratorRef_t iteratorRef, const char *path, double value)
 
bool le_cfg_GetBool (le_cfg_IteratorRef_t iteratorRef, const char *path, bool defaultValue)
 
void le_cfg_SetBool (le_cfg_IteratorRef_t iteratorRef, const char *path, bool value)
 
void le_cfg_QuickDeleteNode (const char *path)
 
void le_cfg_QuickSetEmpty (const char *path)
 
le_result_t le_cfg_QuickGetString (const char *path, char *value, size_t valueSize, const char *defaultValue)
 
void le_cfg_QuickSetString (const char *path, const char *value)
 
int32_t le_cfg_QuickGetInt (const char *path, int32_t defaultValue)
 
void le_cfg_QuickSetInt (const char *path, int32_t value)
 
double le_cfg_QuickGetFloat (const char *path, double defaultValue)
 
void le_cfg_QuickSetFloat (const char *path, double value)
 
bool le_cfg_QuickGetBool (const char *path, bool defaultValue)
 
void le_cfg_QuickSetBool (const char *path, bool value)
 

Detailed Description

Legato Config Tree API include file.

Macro Definition Documentation

#define LE_CFG_NAME_LEN   127

Allowed length of a node name.

#define LE_CFG_NAME_LEN_BYTES   128

The node name length, including a trailing NULL.

#define LE_CFG_STR_LEN   511

Length of the strings used by this API.

#define LE_CFG_STR_LEN_BYTES   512

Length of the strings used by this API, including the trailing NULL.

Typedef Documentation

typedef void(* le_cfg_ChangeHandlerFunc_t) (void *contextPtr)

Handler for node change notifications.

typedef struct le_cfg_ChangeHandler* le_cfg_ChangeHandlerRef_t

Reference type used by Add/Remove functions for EVENT 'le_cfg_Change'

typedef void(* le_cfg_DisconnectHandler_t) (void *)

Type for handler called when a server disconnects.

typedef struct le_cfg_Iterator* le_cfg_IteratorRef_t

Reference to a tree iterator object.

Enumeration Type Documentation

Identifies the type of node.

Enumerator
LE_CFG_TYPE_EMPTY 

A node with no value.

LE_CFG_TYPE_STRING 

A string encoded as utf8.

LE_CFG_TYPE_BOOL 

Boolean value.

LE_CFG_TYPE_INT 

Signed 32-bit.

LE_CFG_TYPE_FLOAT 

64-bit floating point value.

LE_CFG_TYPE_STEM 

Non-leaf node, this node is the parent of other nodes.

LE_CFG_TYPE_DOESNT_EXIST 

Node doesn't exist.

Function Documentation

le_cfg_ChangeHandlerRef_t le_cfg_AddChangeHandler ( const char *  newPath,
le_cfg_ChangeHandlerFunc_t  handlerPtr,
void *  contextPtr 
)

Add handler function for EVENT 'le_cfg_Change'

This event provides information on changes to the given node object, or any of it's children, where a change could be either a read, write, create or delete operation.

Parameters
[in]newPathPath to the object to watch.
[in]handlerPtrHandler to receive change notification
[in]contextPtr
void le_cfg_CancelTxn ( le_cfg_IteratorRef_t  iteratorRef)

Close and free the given iterator object. If the iterator is a write iterator, the transaction will be canceled. If the iterator is a read iterator, the transaction will be closed.

Note
This operation will also delete the iterator object.
Parameters
[in]iteratorRefIterator object to close.
void le_cfg_CommitTxn ( le_cfg_IteratorRef_t  iteratorRef)

Close the write iterator and commit the write transaction. This updates the config tree with all of the writes that occured using the iterator.

Note
This operation will also delete the iterator object.
Parameters
[in]iteratorRefIterator object to commit.
void le_cfg_ConnectService ( void  )

Connect the current client thread to the service providing this API. Block until the service is available.

For each thread that wants to use this API, either ConnectService or TryConnectService must be called before any other functions in this API. Normally, ConnectService is automatically called for the main thread, but not for any other thread. For details, see Client-specific Functions.

This function is created automatically.

le_cfg_IteratorRef_t le_cfg_CreateReadTxn ( const char *  basePath)

Create a read transaction and open a new iterator for traversing the config tree.

Note
This action creates a read lock on the given tree, which will start a read-timeout. Once the read timeout expires, all active read iterators on that tree will be expired and the clients will be killed.
A tree transaction is global to that tree; a long-held read transaction will block other user's write transactions from being comitted.
Returns
This will return a newly created iterator reference.
Parameters
[in]basePathPath to the location to create the new iterator.
le_cfg_IteratorRef_t le_cfg_CreateWriteTxn ( const char *  basePath)

Create a write transaction and open a new iterator for both reading and writing.

Note
This action creates a write transaction. If the app holds the iterator for longer than the configured write transaction timeout, the iterator will cancel the transaction. Other reads will fail to return data, and all writes will be thrown away.
A tree transaction is global to that tree; a long-held write transaction will block other user's write transactions from being started. Other trees in the system won't be affected.
Returns
This will return a newly created iterator reference.
Parameters
[in]basePathPath to the location to create the new iterator.
void le_cfg_DeleteNode ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path 
)

Delete the node specified by the path. If the node doesn't exist, nothing happens. All child nodes are also deleted.

If the path is empty, the iterator's current node is deleted.

Only valid during a write transaction.

Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
void le_cfg_DisconnectService ( void  )

Disconnect the current client thread from the service providing this API.

Normally, this function doesn't need to be called. After this function is called, there's no longer a connection to the service, and the functions in this API can't be used. For details, see Client-specific Functions.

This function is created automatically.

bool le_cfg_GetBool ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
bool  defaultValue 
)

Read a value from the tree as a boolean. If the node is empty or doesn't exist, the default value is returned. Default value is also returned if the node is a different type than expected.

Valid for both read and write transactions.

If the path is empty, the iterator's current node will be read.

Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[in]defaultValueDefault value to use if the original can't be read.
double le_cfg_GetFloat ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
double  defaultValue 
)

Read a 64-bit floating point value from the config tree.

If the value is an integer then the value will be promoted to a float. Otherwise, if the underlying value is not a float or integer, the default value will be returned.

If the path is empty, the iterator's current node will be read.

Note
Floating point values will only be stored up to 6 digits of precision.
Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[in]defaultValueDefault value to use if the original can't be read.
int32_t le_cfg_GetInt ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
int32_t  defaultValue 
)

Read a signed integer value from the config tree.

If the underlying value is not an integer, the default value will be returned instead. The default value is also returned if the node does not exist or if it's empty.

If the value is a floating point value, then it will be rounded and returned as an integer.

Valid for both read and write transactions.

If the path is empty, the iterator's current node will be read.

Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[in]defaultValueDefault value to use if the original can't be read.
le_result_t le_cfg_GetNodeName ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
char *  name,
size_t  nameSize 
)

Get the name of the node where the iterator is currently pointing.

Returns
- LE_OK Read was completed successfully.
  • LE_OVERFLOW Supplied string buffer was not large enough to hold the value.
Parameters
[in]iteratorRefIterator object to use to read from the tree.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[out]nameRead the name of the node object.
[in]nameSize
le_cfg_nodeType_t le_cfg_GetNodeType ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path 
)

Get the type of node where the iterator is currently pointing.

Returns
le_cfg_nodeType_t value indicating the stored value.
Parameters
[in]iteratorRefIterator object to use to read from the tree.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
le_result_t le_cfg_GetPath ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
char *  pathBuffer,
size_t  pathBufferSize 
)

Get path to the node where the iterator is currently pointed.

Assuming the following tree:

1 baseNode/
2  childA/
3  valueA
4  valueB

If the iterator was currently pointing at valueA, GetPath would return the following path:

1 /baseNode/childA/valueA

Optionally, a path to another node can be supplied to this function. So, if the iterator is again on valueA and the relative path ".." is supplied then this function will return the following path:

1 /baseNode/childA/
Returns
- LE_OK - The write was completed successfully.
  • LE_OVERFLOW - The supplied string buffer was not large enough to hold the value.
Parameters
[in]iteratorRefIterator to move.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[out]pathBufferAbsolute path to the iterator's current node.
[in]pathBufferSize
le_result_t le_cfg_GetString ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
char *  value,
size_t  valueSize,
const char *  defaultValue 
)

Read a string value from the config tree. If the value isn't a string, or if the node is empty or doesn't exist, the default value will be returned.

Valid for both read and write transactions.

If the path is empty, the iterator's current node will be read.

Returns
- LE_OK - Read was completed successfully.
  • LE_OVERFLOW - Supplied string buffer was not large enough to hold the value.
Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[out]valueBuffer to write the value into.
[in]valueSize
[in]defaultValueDefault value to use if the original can't be read.
le_result_t le_cfg_GoToFirstChild ( le_cfg_IteratorRef_t  iteratorRef)

Move the iterator to the the first child of the node where the iterator is currently pointed.

For read iterators without children, this function will fail. If the iterator is a write iterator, then a new node is automatically created. If this node or newly created children of this node are not written to, then this node will not persist even if the iterator is comitted.

Returns
Return code will be one of the following values:
    - LE_OK        - Move was completed successfully.
    - LE_NOT_FOUND - The given node has no children.
Parameters
[in]iteratorRefIterator object to move.
le_result_t le_cfg_GoToNextSibling ( le_cfg_IteratorRef_t  iteratorRef)

Jump the iterator to the next child node of the current node. Assuming the following tree:

1 baseNode/
2  childA/
3  valueA
4  valueB

If the iterator is moved to the path, "/baseNode/childA/valueA". After the first GoToNextSibling the iterator will be pointing at valueB. A second call to GoToNextSibling will cause the function to return LE_NOT_FOUND.

Returns
Returns one of the following values:
    - LE_OK            - Commit was completed successfully.
    - LE_NOT_FOUND     - Iterator has reached the end of the current list of siblings.
                         Also returned if the the current node has no siblings.
Parameters
[in]iteratorRefIterator to iterate.
void le_cfg_GoToNode ( le_cfg_IteratorRef_t  iteratorRef,
const char *  newPath 
)

Change the node where the iterator is pointing. The path passed can be an absolute or a relative path from the iterators current location.

The target node does not need to exist. Writing a value to a non-existant node will automatically create that node and any ancestor nodes (parent, parent's parent, etc.) that also don't exist.

Parameters
[in]iteratorRefIterator to move.
[in]newPathAbsolute or relative path from the current location.
le_result_t le_cfg_GoToParent ( le_cfg_IteratorRef_t  iteratorRef)

Move the iterator to the parent of the node.

Returns
Return code will be one of the following values:
    - LE_OK        - Commit was completed successfully.
    - LE_NOT_FOUND - Current node is the root node: has no parent.
Parameters
[in]iteratorRefIterator to move.
bool le_cfg_IsEmpty ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path 
)

Check if the given node is empty. A node is also considered empty if it doesn't yet exist. A node is also considered empty if it has no value or is a stem with no children.

If the path is empty, the iterator's current node is queried for emptiness.

Valid for both read and write transactions.

Returns
A true if the node is considered empty, false if not.
Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
bool le_cfg_NodeExists ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path 
)

Check to see if a given node in the config tree exists.

Returns
True if the specified node exists in the tree. False if not.
Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
void le_cfg_QuickDeleteNode ( const char *  path)

Delete the node specified by the path. If the node doesn't exist, nothing happens. All child nodes are also deleted.

Parameters
[in]pathPath to the node to delete.
bool le_cfg_QuickGetBool ( const char *  path,
bool  defaultValue 
)

Read a value from the tree as a boolean. If the node is empty or doesn't exist, the default value is returned. This is also true if the node is a different type than expected.

If the value is empty or the node doesn't exist, the default value is returned instead.

Parameters
[in]pathPath to the value to write.
[in]defaultValueDefault value to use if the original can't be read.
double le_cfg_QuickGetFloat ( const char *  path,
double  defaultValue 
)

Read a 64-bit floating point value from the config tree. If the value is an integer, then it is promoted to a float. Otherwise, if the underlying value is not a float, or an integer the default value will be returned.

If the value is empty or the node doesn't exist, the default value is returned.

Note
Floating point values will only be stored up to 6 digits of precision.
Parameters
[in]pathPath to the value to write.
[in]defaultValueDefault value to use if the original can't be read.
int32_t le_cfg_QuickGetInt ( const char *  path,
int32_t  defaultValue 
)

Read a signed integer value from the config tree. If the value is a floating point value, then it will be rounded and returned as an integer. Otherwise If the underlying value is not an integer or a float, the default value will be returned instead.

If the value is empty or the node doesn't exist, the default value is returned instead.

Parameters
[in]pathPath to the value to write.
[in]defaultValueDefault value to use if the original can't be read.
le_result_t le_cfg_QuickGetString ( const char *  path,
char *  value,
size_t  valueSize,
const char *  defaultValue 
)

Read a string value from the config tree. If the value isn't a string, or if the node is empty or doesn't exist, the default value will be returned.

Returns
- LE_OK - Commit was completed successfully.
  • LE_OVERFLOW - Supplied string buffer was not large enough to hold the value.
Parameters
[in]pathPath to read from.
[out]valueValue read from the requested node.
[in]valueSize
[in]defaultValueDefault value to use if the original can't be read.
void le_cfg_QuickSetBool ( const char *  path,
bool  value 
)

Write a boolean value to the config tree.

Parameters
[in]pathPath to the value to write.
[in]valueValue to write.
void le_cfg_QuickSetEmpty ( const char *  path)

Make a given node empty. If the node doesn't currently exist then it is created as a new empty node.

Parameters
[in]pathAbsolute or relative path to read from.
void le_cfg_QuickSetFloat ( const char *  path,
double  value 
)

Write a 64-bit floating point value to the config tree.

Note
Floating point values will only be stored up to 6 digits of precision.
Parameters
[in]pathPath to the value to write.
[in]valueValue to write.
void le_cfg_QuickSetInt ( const char *  path,
int32_t  value 
)

Write a signed integer value to the config tree.

Parameters
[in]pathPath to the value to write.
[in]valueValue to write.
void le_cfg_QuickSetString ( const char *  path,
const char *  value 
)

Write a string value to the config tree.

Parameters
[in]pathPath to the value to write.
[in]valueValue to write.
void le_cfg_RemoveChangeHandler ( le_cfg_ChangeHandlerRef_t  handlerRef)

Remove handler function for EVENT 'le_cfg_Change'

Parameters
[in]handlerRef
void le_cfg_SetBool ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
bool  value 
)

Write a boolean value to the config tree. Only valid during a write transaction.

If the path is empty, the iterator's current node will be set.

Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[in]valueValue to write.
void le_cfg_SetEmpty ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path 
)

Clear out the nodes's value. If it doesn't exist it will be created, but have no value.

If the path is empty, the iterator's current node will be cleared. If the node is a stem then all children will be removed from the tree.

Only valid during a write transaction.

Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
void le_cfg_SetFloat ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
double  value 
)

Write a 64-bit floating point value to the config tree. Only valid during a write transaction.

If the path is empty, the iterator's current node will be set.

Note
Floating point values will only be stored up to 6 digits of precision.
Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[in]valueValue to write.
void le_cfg_SetInt ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
int32_t  value 
)

Write a signed integer value to the config tree. Only valid during a write transaction.

If the path is empty, the iterator's current node will be set.

Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[in]valueValue to write.
void le_cfg_SetServerDisconnectHandler ( le_cfg_DisconnectHandler_t  disconnectHandler,
void *  contextPtr 
)

Set handler called when server disconnection is detected.

When a server connection is lost, call this handler then exit with LE_FATAL. If a program wants to continue without exiting, it should call longjmp() from inside the handler.

void le_cfg_SetString ( le_cfg_IteratorRef_t  iteratorRef,
const char *  path,
const char *  value 
)

Write a string value to the config tree. Only valid during a write transaction.

If the path is empty, the iterator's current node will be set.

Parameters
[in]iteratorRefIterator to use as a basis for the transaction.
[in]pathPath to the target node. Can be an absolute path, or a path relative from the iterator's current position.
[in]valueValue to write.
le_result_t le_cfg_TryConnectService ( void  )

Try to connect the current client thread to the service providing this API. Return with an error if the service is not available.

For each thread that wants to use this API, either ConnectService or TryConnectService must be called before any other functions in this API. Normally, ConnectService is automatically called for the main thread, but not for any other thread. For details, see Client-specific Functions.

This function is created automatically.

Returns
  • LE_OK if the client connected successfully to the service.
  • LE_UNAVAILABLE if the server is not currently offering the service to which the client is bound.
  • LE_NOT_PERMITTED if the client interface is not bound to any service (doesn't have a binding).
  • LE_COMM_ERROR if the Service Directory cannot be reached.