~mdw / mLib / blame
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|---|---|---|
| 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 | |
| 4729aa69 MW |
29 | .B "typedef struct { ...\& } dspool;" |
| 30 | ||
| b6b9d458 | 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 | ||
| d2a91066 | 36 | .BI "void DSGET(dspool *" p ", " d ); |
| b6b9d458 | 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 | |
| d2a91066 | 51 | .I isz |
| b6b9d458 | 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 | |
| 08da152e | 87 | .BR sub (3) |
| b6b9d458 | 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 | |
| 08da152e | 92 | .BR dstr (3), |
| 93 | .BR sub (3), | |
| 94 | .BR mLib (3). | |
| b6b9d458 | 95 | .SH AUTHOR |
| 9b5ac6ff | 96 | Mark Wooding, <mdw@distorted.org.uk> |