… | |
… | |
26 | substr $many_cbor_strings, 0, $length, ""; # remove decoded cbor string |
26 | substr $many_cbor_strings, 0, $length, ""; # remove decoded cbor string |
27 | } |
27 | } |
28 | |
28 | |
29 | =head1 DESCRIPTION |
29 | =head1 DESCRIPTION |
30 | |
30 | |
31 | WARNING! This module is very new, and not very well tested (that's up to |
31 | WARNING! This module is very new, and not very well tested (that's up |
32 | you to do). Furthermore, details of the implementation might change freely |
32 | to you to do). Furthermore, details of the implementation might change |
33 | before version 1.0. And lastly, the object serialisation protocol depends |
33 | freely before version 1.0. And lastly, most extensions depend on an IANA |
34 | on a pending IANA assignment, and until that assignment is official, this |
34 | assignment, and until that assignment is official, this implementation is |
35 | implementation is not interoperable with other implementations (even |
35 | not interoperable with other implementations (even future versions of this |
36 | future versions of this module) until the assignment is done. |
36 | module) until the assignment is done. |
37 | |
37 | |
38 | You are still invited to try out CBOR, and this module. |
38 | You are still invited to try out CBOR, and this module. |
39 | |
39 | |
40 | This module converts Perl data structures to the Concise Binary Object |
40 | This module converts Perl data structures to the Concise Binary Object |
41 | Representation (CBOR) and vice versa. CBOR is a fast binary serialisation |
41 | Representation (CBOR) and vice versa. CBOR is a fast binary serialisation |
… | |
… | |
54 | data, the worse L<Storable> performs in comparison. |
54 | data, the worse L<Storable> performs in comparison. |
55 | |
55 | |
56 | As for compactness, C<CBOR::XS> encoded data structures are usually about |
56 | As for compactness, C<CBOR::XS> encoded data structures are usually about |
57 | 20% smaller than the same data encoded as (compact) JSON or L<Storable>. |
57 | 20% smaller than the same data encoded as (compact) JSON or L<Storable>. |
58 | |
58 | |
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59 | In addition to the core CBOR data format, this module implements a number |
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60 | of extensions, to support cyclic and self-referencing data structures |
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61 | (see C<allow_sharing>), string deduplication (see C<allow_stringref>) and |
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62 | scalar references (always enabled). |
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63 | |
59 | The primary goal of this module is to be I<correct> and the secondary goal |
64 | The primary goal of this module is to be I<correct> and the secondary goal |
60 | is to be I<fast>. To reach the latter goal it was written in C. |
65 | is to be I<fast>. To reach the latter goal it was written in C. |
61 | |
66 | |
62 | See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and |
67 | See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and |
63 | vice versa. |
68 | vice versa. |
… | |
… | |
184 | |
189 | |
185 | This means that such values will only be encoded once, and will not result |
190 | This means that such values will only be encoded once, and will not result |
186 | in a deep cloning of the value on decode, in decoders supporting the value |
191 | in a deep cloning of the value on decode, in decoders supporting the value |
187 | sharing extension. |
192 | sharing extension. |
188 | |
193 | |
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194 | It is recommended to leave it off unless you know your |
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195 | communication partner supports the value sharing extensions to CBOR |
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196 | (http://cbor.schmorp.de/value-sharing). |
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197 | |
189 | Detecting shared values incurs a runtime overhead when values are encoded |
198 | Detecting shared values incurs a runtime overhead when values are encoded |
190 | that have a reference counter large than one, and might unnecessarily |
199 | that have a reference counter large than one, and might unnecessarily |
191 | increase the encoded size, as potentially shared values are encode as |
200 | increase the encoded size, as potentially shared values are encode as |
192 | sharable whether or not they are actually shared. |
201 | sharable whether or not they are actually shared. |
193 | |
202 | |
… | |
… | |
199 | |
208 | |
200 | If C<$enable> is false (the default), then C<encode> will encode |
209 | If C<$enable> is false (the default), then C<encode> will encode |
201 | exception when it encounters anything it cannot encode as CBOR. |
210 | exception when it encounters anything it cannot encode as CBOR. |
202 | |
211 | |
203 | This option does not affect C<decode> in any way - shared values and |
212 | This option does not affect C<decode> in any way - shared values and |
204 | references will always be decoded properly if present. It is recommended |
213 | references will always be decoded properly if present. |
205 | to leave it off unless you know your communications partner supports the |
214 | |
206 | value sharing extensions to CBOR (http://cbor.schmorp.de/value-sharing). |
215 | =item $cbor = $cbor->allow_stringref ([$enable]) |
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216 | |
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217 | =item $enabled = $cbor->get_allow_stringref |
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218 | |
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219 | If C<$enable> is true (or missing), then C<encode> will try not to encode |
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220 | the same string twice, but will instead encode a reference to the string |
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221 | instead. Depending on your data format. this can save a lot of space, but |
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222 | also results in a very large runtime overhead (expect encoding times to be |
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223 | 2-4 times as high as without). |
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224 | |
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225 | It is recommended to leave it off unless you know your |
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226 | communications partner supports the stringref extension to CBOR |
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227 | (http://cbor.schmorp.de/stringref). |
|
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228 | |
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229 | If C<$enable> is false (the default), then C<encode> will encode |
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230 | exception when it encounters anything it cannot encode as CBOR. |
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231 | |
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232 | This option does not affect C<decode> in any way - string references will |
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233 | always be decoded properly if present. |
207 | |
234 | |
208 | =item $cbor_data = $cbor->encode ($perl_scalar) |
235 | =item $cbor_data = $cbor->encode ($perl_scalar) |
209 | |
236 | |
210 | Converts the given Perl data structure (a scalar value) to its CBOR |
237 | Converts the given Perl data structure (a scalar value) to its CBOR |
211 | representation. |
238 | representation. |
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621 | =item <unassigned>, <unassigned> (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>) |
648 | =item <unassigned>, <unassigned> (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>) |
622 | |
649 | |
623 | These tags are automatically decoded when encountered, resulting in |
650 | These tags are automatically decoded when encountered, resulting in |
624 | shared values in the decoded object. They are only encoded, however, when |
651 | shared values in the decoded object. They are only encoded, however, when |
625 | C<allow_sharable> is enabled. |
652 | C<allow_sharable> is enabled. |
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653 | |
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654 | =item <unassigned>, <unassigned> (stringref-namespace, stringref, L <http://cbor.schmorp.de/stringref>) |
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655 | |
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656 | These tags are automatically decoded when encountered. They are only |
|
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657 | encoded, however, when C<allow_stringref> is enabled. |
626 | |
658 | |
627 | =item 22098 (indirection, L<http://cbor.schmorp.de/indirection>) |
659 | =item 22098 (indirection, L<http://cbor.schmorp.de/indirection>) |
628 | |
660 | |
629 | This tag is automatically generated when a reference are encountered (with |
661 | This tag is automatically generated when a reference are encountered (with |
630 | the exception of hash and array refernces). It is converted to a reference |
662 | the exception of hash and array refernces). It is converted to a reference |