Wiki source code of Filesystem store
Last modified by Thomas Mortagne on 2024/06/24
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| author | version | line-number | content |
|---|---|---|---|
| 1 | {{box cssClass="floatinginfobox" title="**Contents**"}}{{toc start="2"/}}{{/box}} | ||
| 2 | |||
| 3 | By default in XWiki the content of attachments and deleted attachments and documents are stored in what we call the "filesystem store". Its default location is ##<permanentdir>/store/file##. | ||
| 4 | |||
| 5 | It's a simple file based storage in which documents and attachments references are (md5) hashed, to avoid problems with various limited (in terms of encoding and path size) file systems. The filesystem store implements a two stage commit mechanism to maintain integrity even if the database fails to commit the attachment meta-data for example. | ||
| 6 | |||
| 7 | For example the attachment ##XWikiLogo.png## in document ##Sandbox.WebHome## is stored in the following location: ##/1/0/5d42329a923e687f5dff4887d80098/attachments/9/2/0bc685fa0da28168319c0126def81b##. | ||
| 8 | |||
| 9 | {{box title="And where is my entity located ?"}} | ||
| 10 | {{velocity}} | ||
| 11 | {{html}} | ||
| 12 | <form> | ||
| 13 | <input type="text" name="reference"#if($request.reference) value="$escapetool.xml($request.reference)#end"/> | ||
| 14 | <button name="serialize_document">Document</button> | ||
| 15 | <button name="serialize_attachment">Attachment</button> | ||
| 16 | </form> | ||
| 17 | {{/html}} | ||
| 18 | {{/velocity}} | ||
| 19 | |||
| 20 | {{groovy}} | ||
| 21 | def hash(str) | ||
| 22 | { | ||
| 23 | md5 = org.apache.commons.codec.digest.DigestUtils.md5Hex(str) | ||
| 24 | println "1. It's then md5 hashed (##${md5}##)." | ||
| 25 | |||
| 26 | char0 = md5.charAt(0) | ||
| 27 | println "1. A first folder is created with the first character of the hash (##${char0}##)." | ||
| 28 | |||
| 29 | char1 = md5.charAt(1) | ||
| 30 | println "1. A second folder is created with the second character of the hash (##${char1}##)." | ||
| 31 | |||
| 32 | charn = md5.substring(2) | ||
| 33 | println "1. A third folder is created with the remaining characters (##${charn}##)." | ||
| 34 | |||
| 35 | return "**$char0**/**$char1**/**$charn**" | ||
| 36 | } | ||
| 37 | |||
| 38 | def encodeDocument(documentReference) { | ||
| 39 | path = "" | ||
| 40 | if (documentReference.root.type == org.xwiki.model.EntityType.WIKI) { | ||
| 41 | println "1. A folder with the wiki name (##${documentReference.root.name}##) is created." | ||
| 42 | path = documentReference.root.name | ||
| 43 | } | ||
| 44 | |||
| 45 | localuid = services.component.getInstance(org.xwiki.model.reference.EntityReferenceSerializer.TYPE_STRING, "local/uid").serialize(documentReference) | ||
| 46 | println "1. The document reference is serialized using the local uid serializer (##${localuid}##)." | ||
| 47 | |||
| 48 | path += "/" + hash(localuid) | ||
| 49 | |||
| 50 | return path; | ||
| 51 | } | ||
| 52 | |||
| 53 | def encodeAttachment(attachmentReference) { | ||
| 54 | path = "" | ||
| 55 | if (reference.parent) { | ||
| 56 | path = encodeDocument(attachmentReference.parent) | ||
| 57 | } | ||
| 58 | |||
| 59 | path += "/attachments" | ||
| 60 | println "1. An ##attachments## folder is created." | ||
| 61 | |||
| 62 | name = attachmentReference.name | ||
| 63 | println "1. The attachment name (##$name##) is extracted from the reference." | ||
| 64 | |||
| 65 | path += "/" + hash(name) + "" | ||
| 66 | } | ||
| 67 | |||
| 68 | if (request.serialize_document != null) { | ||
| 69 | reference = services.component.getInstance(org.xwiki.model.reference.EntityReferenceResolver.TYPE_STRING, "relative").resolve(request.reference, org.xwiki.model.EntityType.DOCUMENT) | ||
| 70 | |||
| 71 | println "{{info}}" | ||
| 72 | path = encodeDocument(reference) | ||
| 73 | println "{{/info}}" | ||
| 74 | |||
| 75 | println "" | ||
| 76 | print "The final path of the folder which contains the content of this attachment is ##$path##." | ||
| 77 | } else if (request.serialize_attachment != null) { | ||
| 78 | reference = services.component.getInstance(org.xwiki.model.reference.EntityReferenceResolver.TYPE_STRING, "relative").resolve(request.reference, org.xwiki.model.EntityType.ATTACHMENT) | ||
| 79 | |||
| 80 | println "{{info}}" | ||
| 81 | path = encodeAttachment(reference) | ||
| 82 | println "{{/info}}" | ||
| 83 | |||
| 84 | println "" | ||
| 85 | print "The final path of the folder which contains the content of this document is ##$path##." | ||
| 86 | } | ||
| 87 | {{/groovy}} | ||
| 88 | {{/box}} | ||
| 89 | |||
| 90 | == Attachments and deleted attachments | ||
| 91 | |||
| 92 | By default, inside the attachment folder, you will find both the current version of the attachment and its history. The file name is always ##f##, it's then optionally followed by the version (when it's a piece of the history) and the original file extension. | ||
| 93 | |||
| 94 | For example for an image of type png: | ||
| 95 | |||
| 96 | * ##f.png## | ||
| 97 | * ##fv1.1.png## | ||
| 98 | * ##fv2.1.png## | ||
| 99 | |||
| 100 | {{version since="16.4.0"}} | ||
| 101 | Most of the time, instead of the current version of the attachment, a "link" is created. It's a file which name is suffixed with ##.lnk## which contains the relative path it's representing. In standard condition, it always points to the latest version of the attachment. | ||
| 102 | |||
| 103 | For example for an image of type png: | ||
| 104 | |||
| 105 | * ##f.png.lnk## {{info}}contains the string ##fv2.1.png##{{/info}} | ||
| 106 | * ##fv1.1.png## | ||
| 107 | * ##fv2.1.png## | ||
| 108 | {{/version}} | ||
| 109 | |||
| 110 | The different between attachments and deleted attachment is the location of that folder inside the document folder: | ||
| 111 | * an attachment is located in ##/attachments/<hash/based/on the attachment name>/## | ||
| 112 | * a deleted is located in ##/deleted-attachments/<hash/based/on the attachment name>/<index of the deleted attachment>/## | ||
| 113 | |||
| 114 | == Deleted documents | ||
| 115 | |||
| 116 | {{todo/}} |
