| | 1 | .\" -*-nroff-*- |
| | 2 | .de VS |
| | 3 | .sp 1 |
| | 4 | .in +5n |
| | 5 | .ft B |
| | 6 | .nf |
| | 7 | .. |
| | 8 | .de VE |
| | 9 | .ft R |
| | 10 | .in -5n |
| | 11 | .sp 1 |
| | 12 | .fi |
| | 13 | .. |
| | 14 | .TH dspool 3 "20 June 1999" "Straylight/Edgeware" "mLib utilities library" |
| | 15 | .SH NAME |
| | 16 | dspool \- pools of preallocated dynamic strings |
| | 17 | .\" @dspool_create |
| | 18 | .\" @dspool_destroy |
| | 19 | .\" @dspool_get |
| | 20 | .\" @dspool_put |
| | 21 | .\" |
| | 22 | .\" @DSGET |
| | 23 | .\" @DSPUT |
| | 24 | .\" |
| | 25 | .SH SYNOPSIS |
| | 26 | .nf |
| | 27 | .B "#include <mLib/dspool.h>" |
| | 28 | |
| | 29 | .B "typedef struct { ...\& } dspool;" |
| | 30 | |
| | 31 | .BI "void dspool_create(dspool *" p ", size_t " isz ); |
| | 32 | .BI "void dspool_destroy(dspool *" p ); |
| | 33 | .BI "dstr *dspool_get(dspool *" p ); |
| | 34 | .BI "void dspool_put(dspool *" p ", dstr *" d ); |
| | 35 | |
| | 36 | .BI "void DSGET(dspool *" p ", " d ); |
| | 37 | .BI "void DSPUT(dspool *" p ", dstr *" d ); |
| | 38 | .fi |
| | 39 | .SH DESCRIPTION |
| | 40 | A dynamic string pool maintains a collection of `spare' dynamic |
| | 41 | strings. Some pieces of code require high turnover of strings, and |
| | 42 | allocating and freeing them entails a large amount of overhead. A |
| | 43 | dynamic string pool keeps a list of dynamic strings which have been |
| | 44 | allocated but are not currently in use. |
| | 45 | .PP |
| | 46 | A pool is created by the function |
| | 47 | .BR dspool_create . |
| | 48 | It is passed the address of a pool structure |
| | 49 | .I p |
| | 50 | and the initial size |
| | 51 | .I isz |
| | 52 | to allocate for new dynamic strings obtained from the pool. A newly |
| | 53 | created pool contains no strings. Once a pool is no longer required, |
| | 54 | the function |
| | 55 | .B dspool_destroy |
| | 56 | will release all the strings in the pool, such that the pool can safely |
| | 57 | be thrown away. |
| | 58 | .PP |
| | 59 | A string is obtained from a pool by calling |
| | 60 | .BR dspool_get . |
| | 61 | If the pool is empty, a new string is allocated; otherwise a string is |
| | 62 | chosen from those currently in the pool. |
| | 63 | .PP |
| | 64 | A string is returned to the pool by the |
| | 65 | .B dspool_put |
| | 66 | function. It is passed the address of a pool and the address of a |
| | 67 | string to return. The string must have been allocated from |
| | 68 | .I some |
| | 69 | dynamic string pool, although it's not actually necessary to return it |
| | 70 | to the pool from which it was allocated. |
| | 71 | .PP |
| | 72 | The macro call |
| | 73 | .VS |
| | 74 | DSGET(p, d); |
| | 75 | .VE |
| | 76 | is equivalent to the assignment |
| | 77 | .VS |
| | 78 | d = dspool_get(p); |
| | 79 | .VE |
| | 80 | (except that it's probably quicker). The macro |
| | 81 | .B DSPUT |
| | 82 | is entirely equivalent to the function |
| | 83 | .B dspool_put |
| | 84 | except for improved performance. |
| | 85 | .SH CAVEATS |
| | 86 | The string pool allocator requires the suballocator (see |
| | 87 | .BR sub (3) |
| | 88 | for details). You must ensure that |
| | 89 | .B sub_init |
| | 90 | is called before any strings are allocated from a string pool. |
| | 91 | .SH SEE ALSO |
| | 92 | .BR dstr (3), |
| | 93 | .BR sub (3), |
| | 94 | .BR mLib (3). |
| | 95 | .SH AUTHOR |
| | 96 | Mark Wooding, <mdw@distorted.org.uk> |
~mdw / mLib / blame_incremental