smbase: A Utility Library
Introduction
"smbase" stands for Scott McPeak's Base Library (sorry, naming things
is not my specialty). It's a bunch of
utility modules I use in virtually all of my projects. The entire
library is in the public domain.
There is some overlap in functionality between smbase and the C++
Standard Library. Partly this is because smbase predates the standard
library, and partly this is because that library has aspects to its
design that I disagree with (for example, I think it is excessively
templatized, given flaws in the C++ template mechanism). However, the
intent is that client code can use smbase and the standard library at
the same time.
smbase has developed organically, in response to specific needs.
While each module individually has been reasonably carefully designed,
the library as a whole has not. Consequently, the modules to not
always orthogonally cover a given design space, and some of the
modules are now considered obsolete (marked below as such).
Some of the links below refer to generated documentation files. If
you are reading this from your local filesystem, you may have to
say "make gendoc" (after "./configure") to get them.
Build Instructions
$ ./configure
$ make
$ make check
./configure understands
these options. You can also
look at the Makefile.
Modules
The following sections list all the smbase modules, grouped by
functionality.
Linked Lists
Linked lists are sequences of objects with O(1) insertion at the front
and iterators for traversal. Most also have mutators for
traversing and modifying.
The two main lists classes are ObjList and SObjList. Both are lists
of pointers to objects; the former owns the objects, and will
delete them when it goes away, while the latter does not.
- objlist.h:
ObjList, a general linked list of objects. ObjList considers itself
to "own" (be responsible for deallocating) the things on its list.
See also sobjlist.h.
- sobjlist.h:
SObjList, a general linked list of objects. SObjList does not
consider itself the owner of the list elements. The "s" in the
name stands for "serf", which I use to mean the opposite of "owner".
See also objlist.h.
- xobjlist.h:
This file is processed by M4
to make objlist.h and sobjlist.h.
- voidlist.h,
voidlist.cc:
The core of the linked list implementation used by
objlist.h and sobjlist.h.
There are a couple of variants that support O(1) appending.
Finally, two stacks implemented with lists. Recently, I've been
preferring to use array-based stacks (array.h),
so these are somewhat obsolete.
- objstack.h:
ObjStack, a stack of owned objects. Built with a linked list.
- sobjstack.h:
SObjStack, a stack of non-owned objects. Built with a linked list.
Arrays
Arrays are sequences of objects with O(1) random access and replacement.
The main array header, array.h, contains several
array classes. GrowArray supports bounds checking and a method to
grow the array. ArrayStack supports a distinction between the length
of the sequence and the size of the array allocated to store it,
and grows the latter automatically.
- array.h:
Several array-like template classes, including growable arrays.
The other array modules are less-used.
- arrayqueue.h:
ArrayQueue, a template class implementing a queue with an array.
Supports O(1) enqueue and dequeue.
- datablok.h,
datablok.cpp:
DataBlock, an array of characters of a given length. Useful when the
data may contain NUL ('\0') bytes.
- growbuf.h,
growbuf.cc:
Extension of DataBlock (datablok.h) that
provides an append() function.
This is obsolete.
- arraymap.h:
ArrayMap, a map from integers to object pointers. Obsolete.
Arrays of Bits
Arrays of bits are handled specially, because they are implemented by
storing multiple bits per byte.
Hash Tables and Maps
Maps support mapping from arbitrary domains to arbitrary ranges. Mappings
can be added and queried in amortized O(1) time, but the constant factor
is considerably higher than for arrays and lists.
Probably the most common map is the PtrMap template, which will map
from pointers to pointers, for arbitrary pointed-to types.
If the key can always be derived from the data (for example, the key
is stored in the data object), then it is inefficient to store both in
the table. The following variants require a function pointer to map
from data to keys.
- hashtbl.h,
hashtbl.cc:
HashTable, a hash table. Maps void* to void*.
- thashtbl.h:
Template class built on top of HashTable. Maps KEY* to VALUE*.
- ohashtbl.h:
OwnerHashTable, a hash table that owns the values, built on top
of HashTable. Maps void* to T*.
The above can be used to efficiently implement a set of T*.
- sobjset.h:
SObjSet, a non-owning set of objects implemented on top of HashTable.
There are two specialized versions that combine O(1) insertion
and query of a hash table with O(1) enqueue and dequeue of an
array.
- okhasharr.h:
OwnerKHashArray, a combination of an owner hash table and an array/stack.
- okhashtbl.h:
OwnerKHashTable, a version of okhasharr.h
with type-safe keys ("k" for keys).
Maps with Strings as Keys
Mapping from strings is a nontrivial extension of the above maps
because comparison is more than a pointer equality test. So there
are some specialized maps from strings.
If you have a function that can map from data to (string) key,
then StringHash and TStringHash (the template version) are the
most efficient:
- strhash.h,
strhash.cc:
StringHash, a case-sensitive map from strings to void* pointers.
Built on top of HashTable.
The StringVoidDict and templates wrapped around it are more general.
They do not require a function to map from data to key, support
query-then-modify-result, and alphabetic iteration.
- strobjdict.h:
StringObjDict, a case-sensitive map from strings to object pointers.
The dictionary owns the referred-to objects.
- strsobjdict.h:
StringSObjDict, a case-sensitive map from strings to object pointers.
The dictionary does not own the referred-to objects.
- svdict.h,
svdict.cc:
StringVoidDict, a case-sensitive map from strings to void* pointers.
Built on top of StringHash.
Finally, there is a module to map from strings to strings.
- strdict.h,
strdict.cc:
StringDict, a case-sensitive map from strings to strings.
Currently, this is implemented with a linked list and consequently
not efficient. But it will work when efficiency does not matter,
and could be reimplemented (preserving the interface) with something
better.
Strings
Strings are sequences of characters.
- str.h,
str.cpp:
The string class itself. Using the string class instead of
char* makes handling strings as convenent as manipulating
fundamental types like int or float.
See also string.txt.
- stringset.h,
stringset.cc:
StringSet, a set of strings.
- strtokp.h,
strtokp.cpp:
StrtokParse, a class that parses a string similar to how strtok()
works, but provides a more convenient (and thread-safe) interface.
Similar to Java's StringTokenizer.
- strutil.h,
strutil.cc:
A set of generic string utilities, including replace(), translate(),
trimWhitespace(), encodeWithEscapes(), etc.
- smregexp.h,
smregexp.cc:
Regular expression matching.
System Utilities
The following modules provide access to or wrappers around various
low-level system services.
- autofile.h,
autofile.cc:
AutoFILE, a simple wrapper around FILE* to open it or throw
an exception, and automatically close it.
- cycles.h
cycles.c:
Report total number of processor cycles since the machine was turned on.
Uses the RDTSC instruction on x86.
- missing.h,
missing.cpp:
Implementations of a few C library functions that are not present
on all platforms.
- mypopen.h,
mypopen.c:
Open a process, yielding two pipes: one for writing, one for reading.
- mysig.h,
mysig.cc:
Some signal-related utilities.
- syserr.h,
syserr.cpp:
Intended to be a portable encapsulation of system-dependent error
facilities like UNIX's errno and Win32's GetLastError(). It's not
very complete right now.
- unixutil.h,
unixutil.c:
Some utilities on top of unix functions: writeAll(), readString().
Portability
These modules help insulate client code from the details of the system
it is running on.
- nonport.h,
nonport.cpp:
A library of utility functions whose implementation is system-specific.
Generally, I try to encapsulate all system depenencies as functions
defined in nonport.
- macros.h:
A bunch of useful macros.
- typ.h:
Some type definitions like byte and bool, plus a few
utility macros. Not clearly distinguished from macros.h
in purpose.
Allocation
These modules provide additional control over the allocator.
- ckheap.h:
Interface to check heap integrity. The underlying malloc implementation
must support these entry points for it to work. I've extended Doug
Lea's malloc (malloc.c) to do so.
- malloc.c:
Version 2.7.0 of
Doug Lea's malloc.
I've made some modifications to help with debugging of memory errors
in client code.
- objpool.h:
ObjPool, a custom allocator for fixed-size objects with embedded
'next' links.
Exceptions
These modules define or throw exceptions.
- exc.h,
exc.cpp:
Various exception classes. The intent is derive everything from xBase,
so a program can catch this one exception type in main() and be assured
no exception will propagate out of the program (or any other unit of
granularity you want).
- xassert.h:
xassert is an assert()-like macro that throws an exception when it
fails, instead of calling abort().
Serialization
The "flatten" serialization scheme is intended to allow sets of objects
to read and write themselves to files.
- bflatten.h,
bflatten.cc:
Implementation of the Flatten interface (flatten.h)
for reading/writing binary files.
- flatten.h,
flatten.cc:
Generic interface for serializing in-memory data structures to files.
Similar to Java's Serializable, but independently conceived, and has
superior version control facilities.
Compiler/Translator Support
smbase has a number of modules that are of use to programs that
read and/or write source code.
- hashline.h,
hashline.cc:
HashLineMap, a mechanism for keeping track of #line directives in C
source files. Provides efficient queries with respect to a set of
such directives.
- srcloc.h,
srcloc.cc:
This module maintains a one-word data type called SourceLoc.
SourceLoc is a location within some file, e.g. line/col or character
offset information. SourceLoc also encodes which file it
refers to. This type is very useful for language processors (like
compilers) because it efficiently encodes location formation.
Decoding this into human-readable form is slower than incrementally
updating it, but decoding is made somewhat efficient with some
appropriate index structures.
- boxprint.h
boxprint.cc:
BoxPrint functions as an output stream (sort of like cout)
with operations to indicate structure within the emitted text, so that
it can break lines intelligently. It's used as part of a source-code
pretty-printer.
- warn.h,
warn.cpp:
Intended to provide a general interface for user-level warnings; the
design never really worked well.
Testing and Debugging
- breaker.h
breaker.cpp:
Function for putting a breakpoint in, to get debugger control just
before an exception is thrown.
- test.h:
A few test-harness macros.
- trace.h,
trace.cc:
Module for recording and querying a set of debug tracing flags.
It is documented in trace.html.
- trdelete.h,
trdelete.cc:
An operator delete which overwrites the deallocated memory with
0xAA before deallocating it.
Miscellaneous
- crc.h
crc.cpp:
32-bit cyclic redundancy check.
- gprintf.h,
gprintf.c:
General printf; calls a function to emit each piece.
- owner.h:
Owner, a pointer that deallocates its referrent in its destructor.
Similar to auto_ptr in the C++ Standard.
- point.h,
point.cc:
Point, a pair of integers.
Test Drivers
Test drivers. Below are the modules that are purely test drivers
for other modules. They're separated out from the list above to
avoid the clutter.
Utility Scripts
- run-flex.pl:
Perl script to run flex and massage its output for portability.
- sm_config.pm:
This is a Perl module, intended to be used by configure scripts.
It is mostly a library of useful routines, but also reads and writes
some of the main script's global variables.
Module Dependencies
The scan-depends.pl script is capable
of generating a
module dependency description in the
Dot
format. Not all the modules appear; I try to show the most important
modules, and try to avoid making Dot do weird things.
Below is its output.
There's also a Postscript version.
