1 # Overview
2
3 Welcome to the UAP Common Extensions.
4
5 With this library we provide useful data structures and algorithms for common
6 programmatic tasks in the C language. Using the build files, you can create
7 a static and a shared lib containing all units, but you may also use the UCX
8 sources in your project and compile specific units by yourself.
9
10 If you want to use this library, you can [download and install](install.md)
11 the recent version.
12 The source code is also available as Mercurial repository [at our site](https://uap-core.de/hg/ucx/) and
13 on [Source Forge](https://sourceforge.net/p/ucx/code/).
14
15 ## Authors
16
17 Mike Becker [<universe@uap-core.de>](mailto:universe@uap-core.de)
18
19 Olaf Wintermann
20 [<olaf.wintermann@gmail.com>](mailto:olaf.wintermann@gmail.com)
21
22 ## Other Resources
23
24 * [Doxygen Documentation](https://ucx.sourceforge.io/api/)
25 * [Test Coverage Report](https://ucx.sourceforge.io/coverage/)
26
27 ## Changelog
28
29 ### Version 4.0 - preview {collapsible="true"}
30
31 * adds cx_system_page_size() to allocator.h
32 * adds a new (optional) capacity parameter to cxJsonCreateArr() and cxJsonObjPutArr()
33 * adds cxJsonFromString(), cxJsonToString(), and cxJsonToPrettyString()
34 * adds cxJsonClone()
35 * adds cxJsonCompare()
36 * adds cxMapCompare()
37 * adds line continuation support to CxProperties / CxPropertiesConfig
38 * adds cxBufferMaximumCapacity()
39 * adds cxBufferAppendString()
40 * adds CX_BUFFER_DO_NOT_FREE buffer flag
41 * changes the parameter order of cxBufferInit() and cxBufferCreate()
42 * changes cxBufferReserve() to allow reducing the capacity
43 * changes cxBufferTerminate() to automatically shrink the buffer
44 * changes cxBufferTerminate() so that position and size are equal after a successful operation
45 * changes cxBufferPutString() to accept any kind of string that cx_strcast() supports
46 * changes the names of cxDefineDestructor() and cxDefineAdvancedDestructor() to
47 cxSetDestructor() and cxSetdvancedDestructor()
48 * changes the name of cxCollectionCompareFunc() to cxSetCompareFunc()
49 * changes the entire low-level array-list API by making it much simpler
50 * changes the members of CxJson and CxJsonValue
51 * changes the return value of cxJsonObjIter() to CxMapIterator
52 * changes CxTree structure so that it now inherits CX_COLLECTION_BASE
53 * changes cxPropertiesLoad() to directly load properties from a file to a CxMap
54 * changes cxFreeDefault() from a macro to a function so that it can be used as a simple destructor
55 * fixes cxJsonWrite() incorrectly returning non-zero when strings needed to be escaped
56 * fixes cxJsonNext() incorrectly returning CX_JSON_INCOMPLETE_DATA when the input ends with trailing spaces
57 * fixes critical memory leak when using cxMapFree() on a kv-list that is using destructors
58 * fixes critical use-after-free with keys stored in kv-lists
59 * fixes that overwriting items with cxMapPut() in a kv-list did not work
60 * fixes that cxReallocate(), cxReallocateArray(), cx_reallocate(), and cx_reallocatearray()
61 were not returning zero after freeing the memory when passed a size of zero
62 * removes the CX_STR() macro and instead makes the cx_str() inlinable
63 * removes the sort_members feature from CxJsonWriter
64 * removes the source and sink API from properties.h
65 * removes the flush feature from CxBuffer
66 * removes the ability to remove elements from the iterators created with cxIterator() and cxIteratorPtr()
67 * removes several unnecessary convenience functions
68
69 ### Version 3.2 - 2025-11-30 {collapsible="true"}
70
71 * adds cxMempoolTransfer() and cxMempoolTransferObject()
72 * adds support for different destruction strategies in CxMempool
73 * adds new key-value-based list implementation
74 * adds support for integer keys to CxHashKey
75 * adds support for comparing arbitrary strings without explicit call to cx_strcast()
76 * adds clone, union, difference, and intersection functions for CxList and CxMap
77 * adds cxListContains() and cxMapContains()
78 * adds cxListReserve() and cxListShrink()
79 * adds cxListSet()
80 * adds cxListFirst() and cxListLast()
81 * adds cxListRemoveAndGetFirst() and cxListRemoveAndGetLast(),
82 and corresponding macro aliases cxListPopFront() and cxListPop()
83 * adds cxListEmplace(), cxListEmplaceAt(), cxListEmplaceArray(), cxListEmplaceArrayAt(), and cxMapEmplace()
84 * adds cxListInsertUnique() and cxListInsertUniqueArray()
85 * adds cx_array_insert_unique() and various convenience macros
86 * adds cx_linked_list_insert_unique() and cx_linked_list_insert_unique_chain()
87 * adds cxCollectionCompareFunc() to conveniently set a compare function for a collection
88 without needing to access the base struct manually
89 * adds cxBufferShrink()
90 * adds cxBufferPop()
91 * adds cxTreeSize()
92 * adds CX_PRIstr and CX_SFMT macros for formatting UCX strings
93 * adds cx_strcpy() and cx_strcpy_a()
94 * adds cxJsonArrRemove() and cxJsonObjRemove()
95 * adds cxStdlibAllocator and allows changes of cxDefaultAllocator
96 * improves performance of the CxList array list implementation
97 * changes over-aggressively declaring functions as static inline
98 * changes cx_str() and cx_mutstr() to allow NULL strings
99 * changes cx_strcast() to also accept C-strings as input
100 * changes grow strategy for the memory pool to reduce reallocations
101 * changes grow strategy for CxBuffer, which does now take the page size into account
102 * changes the implementation of cx_strreplacen() for improved efficiency
103 * changes all cxListIterator() and cxMapIterator() family of functions to also accept NULL as argument
104 * changes insert_element member function of CxList to accept NULL source and return a pointer to the inserted element
105 * changes the compare function wrapper for pointer lists so that it no longer invokes the actual compare function for NULL pointers
106 * changes struct cx_array_reallocator_s by replacing the four generic data members with two specifically named members
107 * changes cx_array_reserve() so that it reserves exactly the requested capacity (i.e., without overallocation)
108 * changes all other array functions to perform smart overallocation to avoid too many subsequent allocations
109 * changes that binary search and infimum always report the largest index, and supremum always reports the smallest index
110 when the found element appears more than once in the array
111 * fixes critical memory overflow in the stack-based array reallocator (this unfortunately breaks the function signature)
112 * fixes critical bug in cx_array_insert_sorted() that caused an infinite loop when inserting duplicates
113 * fixes mempool implementation not supporting NULL as argument for realloc
114 * fixes mempool implementation not supporting zero as size for realloc
115 * fixes that the elem_count member of an iterator was not updated after removing an element flagged by cxIteratorFlagRemoval()
116 * fixes that starting an iteration in a non-root node incorrectly continues iteration with the siblings of that node
117 * fixes unnecessary allocations in cx_strcat() family of functions
118 * fixes ineffective overflow check in cx_strcat() family of functions
119 * fixes errno value after failing cxBufferSeek() to be consistently EINVAL
120 * fixes implementation of cxBufferTerminate()
121 * fixes that cxBufferWrite() could auto-extend the buffer beyond the configured threshold
122 * fixes allocator arguments for some printf.h functions not being const
123 * fixes that cx_tree_search() did not investigate subtrees with equally good distance
124 * fixes that memory was freed by the wrong allocator in cx_vasprintf_a() when the underlying vsnprintf() failed
125 * removes all functions that create mutating iterators in favor of making all iterators possibly mutating
126 * removes the use of C23 attributes because they don't mix well with GNU attributes in GCC 15
127
128 ### Version 3.1 - 2025-02-11 {collapsible="true"}
129
130 * adds properties.h
131 * adds tree.h
132 * adds json.h
133 * adds locale-independent string to number conversion functions
134 * adds reallocarray() like functions to allocator.h
135 * adds cxIterator() to create iterators over raw C arrays
136 * adds cxIteratorPtr() to create iterators over raw C pointer arrays
137 * adds cx_array_reallocator() and cx_array_default_reallocator
138 * adds several new array and list functions
139 * adds cxBufferReset()
140 * adds cxBufferAppend()
141 * adds cxBufferEnableFlushing() and cxBufferFlush()
142 * adds CX_BUFFER_COPY_ON_WRITE and CX_BUFFER_COPY_ON_EXTEND flags
143 * adds cxBufferWriteFunc and cxBufferReadFunc function pointers (for convenience)
144 * adds cx_cmp_ptr()
145 * adds cx_vcmp_* family of functions
146 * adds cx_sprintf() and several more variants
147 * adds runtime constants to read out the actual SBO sizes
148 * adds improved version of UCX 2 Test framework (now a self-contained header)
149 * adds cx_nmemb() utility function to common.h
150 * changes that CxMap returns own CxMapIterator to save memory in CxIterator
151 * changes name of cxBasicMempoolCreate() to cxMempoolCreateSimple()
152 * changes all functions, for which there is no dedicated xyz_a variant,
153 to accept NULL as allocator argument (in which case a default allocator will be used)
154 * changes the name of destroy functions that actually free the memory to better indicate their behavior
155 * changes cx_strcat variants to allow handling of ENOMEM
156 * changes cx_strcast() to also accept cxstring (and doing nothing in that case)
157 * changes the behavior of cxBufferSeek() to allow offset zero for SEEK_END
158 * moves cx_compare_func typedef to compare.h
159 * moves cx_szmul() to common.h
160 * moves stream copy functions to new streams.h
161 * removes cx_strupper() and cx_strlower() because they only do the right thing in special cases
162 * removes several *_m variants of functions in string.h in favor of automatic conversion
163 * removes utils.h
164 * removes flag_removal function from iterator
165 * removes cxMapDetach() and makes cxMapRemoveAndGet() compatible with both map variants
166 * removes the API for changing the store_pointer property of collections after their creation
167 * removes CMake
168 * removes GTest dependency
169 * removes flags to disable SBO in tests
170 * removes CX_LINKED_LIST_SWAP_SBO_SIZE (it's not really an optimization for linked lists)
171 * fixes cx_strcmp() and cx_strcasecmp() not being useful for lexicographic ordering
172 * fixes cx_hash_key_cxstr() evaluating the argument twice
173 * fixes critical bug that produced wrong results when comparing lists of different type but same size
174 * ends UCX 2.1 long term support
175
176 ### Version 3.0 - 2023-07-09 {collapsible="true"}
177
178 * complete redesign from scratch
179 * collections can now store copies of objects and not just pointers
180 * collections are now dynamically implemented
181 * users of the library can specify own implementations of collections that work with the UCX API
182 * low level API for custom lists that do not use the UCX structures
183 * various fixes and improvements
184 * drops some other, rarely used, features
185 * removes testing implementation from the lib
186
187 ### Version 2.1 - 2019-12-30 {collapsible="true"}
188
189 * adds string replace functions
190 * adds set operations for ` UcxList` and `UcxMap`
191 * adds `sstrcaseprefix()` and `sstrcasesuffix()`
192 * improves Doxygen documentation in ucx/string.h
193 * adds `UcxArray` data type
194 * adds support for CMake builds, but main build system is still autotools
195
196 ### Version 2.0 - 2018-12-28 {collapsible="true"}
197
198 * some uncritical bug fixes
199 * overflow of `sstrnlen` now returns `SIZE_MAX` instead of zero
200 * adds `scstr_t` - a `const char*` variant for sstr_t
201 * renames utility compare functions
202
203 ### Version 1.1 - 2018-05-14 {collapsible="true"}
204
205 * adds missing 32 bit support to integer overflow checks
206 * adds `ucx_buffer_to_sstr()` macro
207 * adds `ucx_avl_free_content()`
208 * adds some more compare and distance functions in utils.h
209 * adds `SFMT()` and `PRIsstr` convenience macros
210 * destructor functions for `*_free_content()` functions are now optional
211
212 ### Version 1.0.1 - 2018-01-21 {collapsible="true"}
213
214 * some bug fixes
215 * adds integer overflow checks
216
217 ### Version 1.0 - 2017-10-28 {collapsible="true"}
218
219 * first stable version of UCX released
220