generic type-free hash container (simple)
Callback function for zhash_freefn method
Create a new, empty hash container
Destroy a hash container and all items in it
Insert item into hash table with specified key and item.
If key is already present returns -1 and leaves existing item unchanged
Returns 0 on success.
Update item into hash table with specified key and item.
If key is already present, destroys old item and inserts new one.
Use free_fn method to ensure deallocator is properly called on item.
Remove an item specified by key from the hash table. If there was no such
item, this function does nothing.
Return the item at the specified key, or null
Reindexes an item from an old key to a new key. If there was no such
item, does nothing. Returns 0 if successful, else -1.
Set a free function for the specified hash table item. When the item is
destroyed, the free function, if any, is called on that item.
Use this when hash items are dynamically allocated, to ensure that
you don't have memory leaks. You can pass 'free' or NULL as a free_fn.
Returns the item, or NULL if there is no such item.
Return the number of keys/items in the hash table
Make copy of hash table; if supplied table is null, returns null.
Does not copy items themselves. Rebuilds new table so may be slow on
very large tables. NOTE: only works with item values that are strings
since there's no other way to know how to duplicate the item value.
Return keys for items in table
Simple iterator; returns first item in hash table, in no given order,
or NULL if the table is empty. This method is simpler to use than the
foreach() method, which is deprecated. To access the key for this item
use zhash_cursor(). NOTE: do NOT modify the table while iterating.
Simple iterator; returns next item in hash table, in no given order,
or NULL if the last item was already returned. Use this together with
zhash_first() to process all items in a hash table. If you need the
items in sorted order, use zhash_keys() and then zlist_sort(). To
access the key for this item use zhash_cursor(). NOTE: do NOT modify
the table while iterating.
After a successful first/next method, returns the key for the item that
was returned. This is a constant string that you may not modify or
deallocate, and which lasts as long as the item in the hash. After an
unsuccessful first/next, returns NULL.
Add a comment to hash table before saving to disk. You can add as many
comment lines as you like. These comment lines are discarded when loading
the file. If you use a null format, all comments are deleted.
Serialize hash table to a binary frame that can be sent in a message.
The packed format is compatible with the 'dictionary' type defined in
http://rfc.zeromq.org/spec:35/FILEMQ, and implemented by zproto:
; A list of name/value pairs
dictionary = dict-count *( dict-name dict-value )
dict-count = number-4
dict-value = longstr
dict-name = string
; Strings are always length + text contents
longstr = number-4 *VCHAR
string = number-1 *VCHAR
; Numbers are unsigned integers in network byte order
number-1 = 1OCTET
number-4 = 4OCTET
Comments are not included in the packed data. Item values MUST be
strings.
Unpack binary frame into a new hash table. Packed data must follow format
defined by zhash_pack. Hash table is set to autofree. An empty frame
unpacks to an empty hash table.
Save hash table to a text file in name=value format. Hash values must be
printable strings; keys may not contain '=' character. Returns 0 if OK,
else -1 if a file error occurred.
Load hash table from a text file in name=value format; hash table must
already exist. Hash values must printable strings; keys may not contain
'=' character. Returns 0 if OK, else -1 if a file was not readable.
When a hash table was loaded from a file by zhash_load, this method will
reload the file if it has been modified since, and is "stable", i.e. not
still changing. Returns 0 if OK, -1 if there was an error reloading the
file.
Set hash for automatic value destruction