| b6b9d458 |
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 | .. |
| fbf20b5b |
14 | .TH dspool 3 "20 June 1999" "Straylight/Edgeware" "mLib utilities library" |
| b6b9d458 |
15 | .SH NAME |
| 16 | dspool \- pools of preallocated dynamic strings |
| 08da152e |
17 | .\" @dspool_create |
| 18 | .\" @dspool_destroy |
| 19 | .\" @dspool_get |
| 20 | .\" @dspool_put |
| 21 | .\" |
| 22 | .\" @DSGET |
| 23 | .\" @DSPUT |
| 24 | .\" |
| b6b9d458 |
25 | .SH SYNOPSIS |
| 26 | .nf |
| d2a91066 |
27 | .B "#include <mLib/dspool.h>" |
| b6b9d458 |
28 | |
| 29 | .BI "void dspool_create(dspool *" p ", size_t " isz ); |
| 30 | .BI "void dspool_destroy(dspool *" p ); |
| 31 | .BI "dstr *dspool_get(dspool *" p ); |
| 32 | .BI "void dspool_put(dspool *" p ", dstr *" d ); |
| 33 | |
| d2a91066 |
34 | .BI "void DSGET(dspool *" p ", " d ); |
| b6b9d458 |
35 | .BI "void DSPUT(dspool *" p ", dstr *" d ); |
| 36 | .fi |
| 37 | .SH DESCRIPTION |
| 38 | A dynamic string pool maintains a collection of `spare' dynamic |
| 39 | strings. Some pieces of code require high turnover of strings, and |
| 40 | allocating and freeing them entails a large amount of overhead. A |
| 41 | dynamic string pool keeps a list of dynamic strings which have been |
| 42 | allocated but are not currently in use. |
| 43 | .PP |
| 44 | A pool is created by the function |
| 45 | .BR dspool_create . |
| 46 | It is passed the address of a pool structure |
| 47 | .I p |
| 48 | and the initial size |
| d2a91066 |
49 | .I isz |
| b6b9d458 |
50 | to allocate for new dynamic strings obtained from the pool. A newly |
| 51 | created pool contains no strings. Once a pool is no longer required, |
| 52 | the function |
| 53 | .B dspool_destroy |
| 54 | will release all the strings in the pool, such that the pool can safely |
| 55 | be thrown away. |
| 56 | .PP |
| 57 | A string is obtained from a pool by calling |
| 58 | .BR dspool_get . |
| 59 | If the pool is empty, a new string is allocated; otherwise a string is |
| 60 | chosen from those currently in the pool. |
| 61 | .PP |
| 62 | A string is returned to the pool by the |
| 63 | .B dspool_put |
| 64 | function. It is passed the address of a pool and the address of a |
| 65 | string to return. The string must have been allocated from |
| 66 | .I some |
| 67 | dynamic string pool, although it's not actually necessary to return it |
| 68 | to the pool from which it was allocated. |
| 69 | .PP |
| 70 | The macro call |
| 71 | .VS |
| 72 | DSGET(p, d); |
| 73 | .VE |
| 74 | is equivalent to the assignment |
| 75 | .VS |
| 76 | d = dspool_get(p); |
| 77 | .VE |
| 78 | (except that it's probably quicker). The macro |
| 79 | .B DSPUT |
| 80 | is entirely equivalent to the function |
| 81 | .B dspool_put |
| 82 | except for improved performance. |
| 83 | .SH CAVEATS |
| 84 | The string pool allocator requires the suballocator (see |
| 08da152e |
85 | .BR sub (3) |
| b6b9d458 |
86 | for details). You must ensure that |
| 87 | .B sub_init |
| 88 | is called before any strings are allocated from a string pool. |
| 89 | .SH SEE ALSO |
| 08da152e |
90 | .BR dstr (3), |
| 91 | .BR sub (3), |
| 92 | .BR mLib (3). |
| b6b9d458 |
93 | .SH AUTHOR |
| 9b5ac6ff |
94 | Mark Wooding, <mdw@distorted.org.uk> |
~mdw / mLib / blame