{"id":3953,"date":"2023-11-01T20:42:27","date_gmt":"2023-11-01T12:42:27","guid":{"rendered":"https:\/\/white-night.club\/?p=3953"},"modified":"2024-08-23T12:03:49","modified_gmt":"2024-08-23T04:03:49","slug":"pg21","status":"publish","type":"post","link":"https:\/\/white-night.club\/index.php\/2023\/11\/01\/pg21\/","title":{"rendered":"MIT6.5830 Lab1-GoDB\u5b9e\u9a8c\u8bb0\u5f55\uff08\u516d\uff09"},"content":{"rendered":"\n

\u8d5b\u535a\u5750\u7262\u4e4b\u65c5\u7b2c\u4e00\u7ae0\u7b2c\u516d\u8282\uff1a\u63a5\u7740\u4e0a\u4e00\u8282\uff0c\u8865\u5168heap_page\u5269\u4e0b\u7684\u51fd\u6570\u3002<\/p>\n\n\n\n

<\/div>\n\n\n\n
\n

\u5f00\u59cb\u5750\u7262<\/p>\n\u5220\u9664tuple<\/em><\/cite><\/blockquote>\n\n\n\n

\u8fd9\u4e2a\u770b\u8d77\u6765…\u96be\u5ea6\u8fd8\u6ca1\u90a3\u4e48\u9ad8\uff0c\u5199\u4e00\u4e0b\u8bd5\u8bd5\u5427\u3002\u90a3\u5c31\u904d\u5386tuple\u7136\u540e\u627erid\u5457\u3002<\/p>\n\n\n\n

Go<\/span><\/path><\/path><\/svg><\/span>
func<\/span> (h *heapPage) <\/span>deleteTuple<\/span>(rid recordID) <\/span>error<\/span> {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\t<\/span>for<\/span> <\/span>i<\/span>, <\/span>tuple<\/span> := <\/span>range<\/span> h.Tuple {<\/span><\/span>\n\t\t<\/span>if<\/span> tuple.Rid == rid {<\/span><\/span>\n\t\t\th.Tuple[i] = <\/span>nil<\/span><\/span>\n\t\t\th.Hdr.UsedSlots -= <\/span>1<\/span><\/span>\n\t\t\t<\/span>return<\/span> <\/span>nil<\/span><\/span>\n\t\t}<\/span><\/span>\n\t}<\/span><\/span>\n\t<\/span>return<\/span> errors.<\/span>New<\/span>(<\/span>"the slot is invalid"<\/span>) <\/span>\/\/replace me<\/span><\/span>\n<\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
\u8dd1\u4e00\u4e0bTestDeleteHeapPage\uff0c\u8fc7\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u786e\u5b9e\u6709\u4e86\u601d\u8def\u4e4b\u540e\u5199\u8d77\u6765\u5f97\u5fc3\u5e94\u624b\uff0c\u63a5\u7740\u5f80\u4e0b\u770b\u770b\u3002<\/p>\n\n\n\n
\u522b\u5fd8\u4e86\u8fd8\u6709\u4e2aTestHeapPageDeleteTuple\uff0c\u8dd1\u4e00\u4e0b\u3002\u55ef\uff1f\u5c45\u7136\u62a5\u9519\u4e86\u3002\u53c8\u662f\u8bbf\u95ee\u8d8a\u754c\u554a\u554a\u554a\u554a\u554a\u554a\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u770b\u770b\u62a5\u9519\u5730\u65b9\u5728\u54ea\u91cc\u3002\u4ed4\u7ec6\u4e00\u770b\uff0ctuple\u6ca1\u5224\u7a7a……………………………tuple\u7b49\u4e8enil\u7684\u8bdd\u62ff\u4e0d\u5230rid\u81ea\u7136\u5c31\u4f1a\u8bbf\u95ee\u8d8a\u754c……………….\u8865\u5168\u4e00\u4e0b<\/p>\n\n\n\n
Go<\/span><\/path><\/path><\/svg><\/span>
func<\/span> (h *heapPage) <\/span>deleteTuple<\/span>(rid recordID) <\/span>error<\/span> {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\t<\/span>for<\/span> <\/span>i<\/span>, <\/span>tuple<\/span> := <\/span>range<\/span> h.Tuple {<\/span><\/span>\n\t\t<\/span>if<\/span> tuple != <\/span>nil<\/span> && tuple.Rid == rid {<\/span><\/span>\n\t\t\th.Tuple[i] = <\/span>nil<\/span><\/span>\n\t\t\th.Hdr.UsedSlots -= <\/span>1<\/span><\/span>\n\t\t\t<\/span>return<\/span> <\/span>nil<\/span><\/span>\n\t\t}<\/span><\/span>\n\t}<\/span><\/span>\n\t<\/span>return<\/span> errors.<\/span>New<\/span>(<\/span>"the slot is invalid"<\/span>) <\/span>\/\/replace me<\/span><\/span>\n<\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
\u518dtest\u4e00\u4e0b\uff0c\u8fc7\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
<\/div>\n\n\n\n
\n
\u5b9e\u9a8c\u6b65\u9aa4<\/p>\ndirty<\/em><\/cite><\/blockquote>\n\n\n\n
\u5224\u65adpage\u662f\u5426\u4e3a\u201c\u810f\u9875\u201d\u548c\u5c06page\u8bbe\u7f6e\u4e3a\u201c\u810f\u9875\u201d\uff0c\u90a3\u8fd8\u5f97\u5728page\u7684\u7ed3\u6784\u91cc\u52a0\u4e2adirty\u3002<\/p>\n\n\n\n
Go<\/span><\/path><\/path><\/svg><\/span>
type<\/span> <\/span>heapPage<\/span> <\/span>struct<\/span> {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\tHdr   Header<\/span><\/span>\n\tTuple []*Tuple<\/span><\/span>\n\tDesc  *TupleDesc<\/span><\/span>\n<\/span>\n\tFile   *HeapFile<\/span><\/span>\n\tPageNo <\/span>int<\/span><\/span>\n\tDirty  <\/span>bool<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
\u8fd9\u4e24\u4e2a\u51fd\u6570\u4e5f\u6ca1\u5565\u8bf4\u7684\uff0c\u633a\u7b80\u5355\u7684\u3002<\/p>\n\n\n\n
Go<\/span><\/path><\/path><\/svg><\/span>
\/\/ Page method - return whether or not the page is dirty<\/span><\/span>\nfunc<\/span> (h *heapPage) <\/span>isDirty<\/span>() <\/span>bool<\/span> {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\t<\/span>return<\/span> h.Dirty <\/span>\/\/replace me<\/span><\/span>\n}<\/span><\/span>\n<\/span>\n\/\/ Page method - mark the page as dirty<\/span><\/span>\nfunc<\/span> (h *heapPage) <\/span>setDirty<\/span>(dirty <\/span>bool<\/span>) {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\t<\/span>h.Dirty<\/span> = dirty<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
\u8fd9\u4e2a\u5c45\u7136\u4e5f\u6709test\uff0c\u90a3\u5c31\u8dd1\u4e00\u4e0b\u5427\uff0c\u8fc7\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u7784\u4e86\u4e00\u773c\u4e0b\u4e00\u4e2atest\uff0c\u5475\u5475\uff0c\u53c8\u662f\u5e8f\u5217\u5316\uff0c\u770b\u6765\u8d5b\u535a\u5750\u7262\u4e4b\u65c5\u8fd8\u5f97\u7ee7\u7eed\u3002<\/p>\n\n\n\n
<\/div>\n\n\n\n
\n
\u5b9e\u9a8c\u6b65\u9aa4<\/p>\n\u8fd4\u56de\u5bf9\u5e94\u7684page<\/em><\/cite><\/blockquote>\n\n\n\n
\u8fd9\u4e2a\u771f\u7684\u96be\u5417\uff1f\u5982\u96be\u3002<\/p>\n\n\n\n
\u597d\u5427\u4ed4\u7ec6\u4e00\u770b\u5b83\u771f\u7684\u6709\u70b9\u96be\u3002\u56e0\u4e3a\u6ce8\u91ca\u5c31\u4e00\u53e5\u8bdd\uff1a\u8fd4\u56de\u5f53\u524dheap page\u6240\u5728\u7684heapFile\u3002<\/p>\n\n\n\n
Go<\/span><\/path><\/path><\/svg><\/span>
\/\/ Page method - return the corresponding HeapFile<\/span><\/span>\n\/\/ for this page.<\/span><\/span>\nfunc<\/span> (p *heapPage) <\/span>getFile<\/span>() *DBFile {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n<\/span>\n\t<\/span>return<\/span> <\/span>nil<\/span> <\/span>\/\/replace me<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
\u6ca1\u5176\u5b83\u63d0\u793a\u4e86\uff0c\u90a3\u6211\u4eec\u53ea\u80fd\u5148\u770b\u770bDBFile\u7684\u5b9a\u4e49\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u55ef…\u7ed9\u7684\u662f\u4e00\u4e2a\u63a5\u53e3\uff0c\u90a3\u4e48DBFile\u5e94\u8be5\u662f\u5305\u542bheapfile\u7684\u3002\u90a3\u76f4\u63a5\u628aheap page\u7684file\u8fd4\u56de\u7ed9\u63a5\u53e3\u4e0d\u5c31\u597d\u4e86…<\/p>\n\n\n\n
Go<\/span><\/path><\/path><\/svg><\/span>
func<\/span> (p *heapPage) <\/span>getFile<\/span>() *DBFile {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\t<\/span>var<\/span> <\/span>dbFile<\/span> DBFile = p.File<\/span><\/span>\n\t<\/span>return<\/span> &dbFile <\/span>\/\/replace me<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
\u6ca1\u6cd5test\uff0c\u56e0\u4e3aGetPage\u8fd8\u6ca1\u5199\u5b8c\uff0c\u90a3\u5c31\u5148….\u8fc7\uff01<\/p>\n\n\n\n
<\/div>\n\n\n\n
\n
\u5b9e\u9a8c\u6b65\u9aa4<\/p>\n\u53c8\u662f\u5e8f\u5217\u5316<\/em><\/cite><\/blockquote>\n\n\n\n
\u5e8f\u5217\u5316\u6211\u662f\u771f\u7684\u4e0d\u719f\u3002\u53ea\u80fd\u786c\u7740\u5934\u76ae\u5199\u4e86\u3002\u5148\u6765\u770b\u770b\u8981\u505a\u4e9b\u4ec0\u4e48\u3002<\/p>\n\n\n\n
Go<\/span><\/path><\/path><\/svg><\/span>
\/\/ Allocate a new bytes.Buffer and write the heap page to it. Returns an error<\/span><\/span>\n\/\/ if the write to the the buffer fails. You will likely want to call this from<\/span><\/span>\n\/\/ your [HeapFile.flushPage] method.  You should write the page header, using<\/span><\/span>\n\/\/ the binary.Write method in LittleEndian order, followed by the tuples of the<\/span><\/span>\n\/\/ page, written using the Tuple.writeTo method.<\/span><\/span>\nfunc<\/span> (h *heapPage) <\/span>toBuffer<\/span>() (*bytes.Buffer, <\/span>error<\/span>) {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\t<\/span><\/span>\n\t<\/span>return<\/span> <\/span>nil<\/span>, <\/span>nil<\/span> <\/span>\/\/replace me<\/span><\/span>\n<\/span>\n}<\/span><\/span>\n<\/span>\n\/\/ Read the contents of the HeapPage from the supplied buffer.<\/span><\/span>\nfunc<\/span> (h *heapPage) <\/span>initFromBuffer<\/span>(buf *bytes.Buffer) <\/span>error<\/span> {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\t<\/span>return<\/span> <\/span>nil<\/span> <\/span>\/\/replace me<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
\u5e8f\u5217\u5316\u548c\u53cd\u5e8f\u5217\u5316\u5728\u4e4b\u524d\u7684tuple\u6211\u4eec\u5df2\u7ecf\u63a5\u89e6\u8fc7\u4e86\uff0c\u90a3\u8fd9\u91cc\u6211\u4eec\u5c31\u76f4\u63a5\u5f00\u5199\u5457\u3002<\/p>\n\n\n\n
\u8001\u6837\u5b50\uff0c\u5148\u662f\u5199\u5165\u7f13\u51b2\u533a\u3002\u611f\u89c9\u6bd4tuple\u7b80\u5355\u4e9b\uff0c\u6bd5\u7adf\u4e0d\u7528\u8003\u8651\u4e0d\u540c\u7684\u5b57\u6bb5fields\u7c7b\u578b\u4e86\u3002<\/p>\n\n\n\n
Go<\/span><\/path><\/path><\/svg><\/span>
func<\/span> (h *heapPage) <\/span>toBuffer<\/span>() (*bytes.Buffer, <\/span>error<\/span>) {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\t<\/span>bytesBuffer<\/span> := <\/span>new<\/span>(bytes.Buffer)<\/span><\/span>\n\t<\/span>err<\/span> := binary.<\/span>Write<\/span>(bytesBuffer, binary.LittleEndian, h.Hdr)<\/span><\/span>\n\t<\/span>if<\/span> err != <\/span>nil<\/span> {<\/span><\/span>\n\t\t<\/span>return<\/span> <\/span>nil<\/span>, err<\/span><\/span>\n\t}<\/span><\/span>\n\t<\/span>for<\/span> <\/span>_<\/span>, <\/span>tuple<\/span> := <\/span>range<\/span> h.Tuple {<\/span><\/span>\n\t\t<\/span>if<\/span> tuple != <\/span>nil<\/span> {<\/span><\/span>\n\t\t\t<\/span>err<\/span> := tuple.<\/span>writeTo<\/span>(bytesBuffer)<\/span><\/span>\n\t\t\t<\/span>if<\/span> err != <\/span>nil<\/span> {<\/span><\/span>\n\t\t\t\t<\/span>return<\/span> <\/span>nil<\/span>, err<\/span><\/span>\n\t\t\t}<\/span><\/span>\n\t\t}<\/span><\/span>\n\t}<\/span><\/span>\n<\/span>\n\t<\/span>return<\/span> bytesBuffer, <\/span>nil<\/span> <\/span>\/\/replace me<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
\u63a5\u4e0b\u6765\u662f\u8bfb\u53d6\u7f13\u51b2\u533a\u3002\u8bfb\u53d6\u7684\u65f6\u5019\u8981\u6ce8\u610f\u8303\u56f4\uff0c\u6bd4\u5982page\u53ef\u7528102\u4e2a\u63d2\u69fd\uff0c\u8868\u793a\u7684\u662f\u4ece0-101\u4e0b\u6807\u7684\u63d2\u69fd\u90fd\u662f\u53ef\u7528\u7684\uff0c\u6240\u4ee5TotalSlots\u8981\u51cf\u4e00\u3002<\/p>\n\n\n\n
Go<\/span><\/path><\/path><\/svg><\/span>
func<\/span> (h *heapPage) <\/span>initFromBuffer<\/span>(buf *bytes.Buffer) <\/span>error<\/span> {<\/span><\/span>\n\t<\/span>\/\/ TODO: some code goes here<\/span><\/span>\n\t<\/span>err<\/span> := binary.<\/span>Read<\/span>(buf, binary.LittleEndian, &h.Hdr)<\/span><\/span>\n\t<\/span>if<\/span> err != <\/span>nil<\/span> {<\/span><\/span>\n\t\t<\/span>return<\/span> err<\/span><\/span>\n\t}<\/span><\/span>\n\t<\/span>for<\/span> <\/span>i<\/span> := <\/span>0<\/span>; i < <\/span>int<\/span>(h.Hdr.TotalSlots)-<\/span>1<\/span>; i++ {<\/span><\/span>\n\t\t<\/span>tuple<\/span>, <\/span>err<\/span> := <\/span>readTupleFrom<\/span>(buf, h.Desc)<\/span><\/span>\n\t\t<\/span>if<\/span> err != <\/span>nil<\/span> {<\/span><\/span>\n\t\t\t<\/span>return<\/span> err<\/span><\/span>\n\t\t}<\/span><\/span>\n\t\th.Tuple[i] = tuple<\/span><\/span>\n\t}<\/span><\/span>\n\t<\/span>return<\/span> <\/span>nil<\/span> <\/span>\/\/replace me<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
run\u4e00\u4e0btest\uff0c\u8fc7\u3002\u81f3\u6b64\u6211\u4eec\u5c31\u5b8c\u6210\u4e86Exercise 3\u7684\u5168\u90e8\u5185\u5bb9\uff0c\u63a5\u4e0b\u6765\u5c31\u662f\u5b8c\u6210Exercise 4\u54af\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Lab1\u5b9e\u9a8c\u8bb0\u5f55\uff1a\u8865\u5168heap_page\u51fd\u6570<\/p>\n","protected":false},"author":1,"featured_media":3960,"comment_status":"open","ping_status":"","sticky":false,"template":"base","format":"standard","meta":{"footnotes":""},"categories":[44,33],"tags":[34],"_links":{"self":[{"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/posts\/3953"}],"collection":[{"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/comments?post=3953"}],"version-history":[{"count":0,"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/posts\/3953\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/media\/3960"}],"wp:attachment":[{"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/media?parent=3953"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/categories?post=3953"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/white-night.club\/index.php\/wp-json\/wp\/v2\/tags?post=3953"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}