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diff --git a/docs/programmer_reference/mp_warm.html b/docs/programmer_reference/mp_warm.html index 402f4203..e4d9fa81 100644 --- a/docs/programmer_reference/mp_warm.html +++ b/docs/programmer_reference/mp_warm.html @@ -14,7 +14,7 @@ <body> <div xmlns="" class="navheader"> <div class="libver"> - <p>Library Version 11.2.5.3</p> + <p>Library Version 12.1.6.1</p> </div> <table width="100%" summary="Navigation header"> <tr> @@ -22,9 +22,7 @@ </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="mp_config.html">Prev</a> </td> - <th width="60%" align="center">Chapter 18. - The Memory Pool Subsystem - </th> + <th width="60%" align="center">Chapter 18. The Memory Pool Subsystem </th> <td width="20%" align="right"> <a accesskey="n" href="txn.html">Next</a></td> </tr> </table> @@ -47,58 +45,61 @@ </dt> </dl> </div> - <p> - Some applications find it is useful to pre-load the memory pool - upon application startup. This is a strictly optional activity that - provides faster initial access to your data at the expense of - longer application startup times. + <p> + Some applications find it is useful to pre-load the memory + pool upon application startup. This is a strictly optional + activity that provides faster initial access to your data at + the expense of longer application startup times. </p> - <p> - To warm the cache, you simply have to read the records that your - application will operate on most frequently. You can do this with - normal database reads, and you can also use cursors. But the most - efficient way to warm the cache is to use memory pool APIs to get - the pages that contain your most frequently accessed records. + <p> + To warm the cache, you simply have to read the records that + your application will operate on most frequently. You can do + this with normal database reads, and you can also use cursors. + But the most efficient way to warm the cache is to use memory + pool APIs to get the pages that contain your most frequently + accessed records. </p> - <p> + <p> You read pages into the memory pool using the - <code class="methodname">DB_MPOOLFILE->get()</code> method. This method - acquires locks on the page, so immediately upon getting the page - you need to put it so as to release the locks. + <code class="methodname">DB_MPOOLFILE->get()</code> method. This + method acquires locks on the page, so immediately upon getting + the page you need to put it so as to release the locks. </p> <p> - Also, you obtain a memory pool file handle using a database handle. - This means that if your data is contained in more than one Berkeley - DB database, you must operate on each database handle in turn. + Also, you obtain a memory pool file handle using a database + handle. This means that if your data is contained in more than + one Berkeley DB database, you must operate on each database + handle in turn. </p> <p> - The following example code illustrates this. It does the following: + The following example code illustrates this. It does the + following: </p> <div class="itemizedlist"> <ul type="disc"> <li> - <p> + <p> Opens an environment and two database handles. </p> </li> <li> <p> - Determines how many database pages can fit into the memory - pool. + Determines how many database pages can fit into the + memory pool. </p> </li> <li> - <p> - Uses <code class="methodname">DB_MPOOLFILE->get()</code> and - <code class="methodname">DB_MPOOLFILE->put()</code> - to load that number of pages into the memory pool. + <p> + Uses <code class="methodname">DB_MPOOLFILE->get()</code> + and <code class="methodname">DB_MPOOLFILE->put()</code> to + load that number of pages into the memory pool. </p> </li> </ul> </div> <p> - First, we include the libraries that we need, forward declare some - functions, and intialize some variables. + First, we include the libraries that we need, forward + declare some functions, and intialize some variables. </p> <a id="prog_mp01-1"></a> <pre class="programlisting">#include <stdio.h> @@ -117,12 +118,12 @@ main(void) DB_ENV *envp = 0; u_int32_t env_flags, pagesize, gbytes, bytes; int ret = 0, ret_t = 0, numcachepages, pagecount; </pre> - <p> + <p> Then we open the environment and our databases. The - <code class="methodname">open_db()</code> function that we use here simply - opens a database. We will provide that code at the end of this - example, but it should hold no surprises for you. - We only use the function so as to reuse the code. + <code class="methodname">open_db()</code> function that we use + here simply opens a database. We will provide that code at the + end of this example, but it should hold no surprises for you. + We only use the function so as to reuse the code. </p> <a id="prog_mp01-2"></a> <pre class="programlisting"> /* @@ -161,9 +162,9 @@ main(void) if (ret != 0) goto err; </pre> <p> - Next we determine how many database pages we can fit into the - cache. We do this by finding out how large our pages are, and then - finding out how large our cache can be. + Next we determine how many database pages we can fit into + the cache. We do this by finding out how large our pages are, + and then finding out how large our cache can be. </p> <a id="prog_mp01-3"></a> <pre class="programlisting"> /* Find out how many pages can fit at most in the cache */ @@ -183,12 +184,12 @@ main(void) /* Avoid an overflow by first calculating pages per gigabyte. */ numcachepages = gbytes * ((1024 * 1024 * 1024) / pagesize); numcachepages += bytes / pagesize; </pre> - <p> + <p> Now we call our <code class="methodname">warm_cache()</code> - function. We will describe this function in a little while, but - note that we call <code class="methodname">warm_cache()</code> + function. We will describe this function in a little while, + but note that we call <code class="methodname">warm_cache()</code> twice. This is because our example uses two databases, and the - memory pool methods operate on a per-handle basis. + memory pool methods operate on a per-handle basis. </p> <a id="prog_mp01-4"></a> <pre class="programlisting"> /* @@ -209,7 +210,7 @@ main(void) db_strerror(ret)); goto err; } </pre> - <p> + <p> Now we close all our handles and finish our <code class="methodname">main()</code> function. Again, this is straight-forward boilerplate code that we provide simply to be @@ -250,11 +251,11 @@ main(void) printf("I'm all done.\n"); return (ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE); } </pre> - <p> - As noted above, this example uses an <code class="methodname">open_db()</code> - function, which opens a database handle inside the provided - environment. To be complete, this is the implementation of that - function: + <p> + As noted above, this example uses an + <code class="methodname">open_db()</code> function, which opens a + database handle inside the provided environment. To be + complete, this is the implementation of that function: </p> <a id="prog_mp01-6"></a> <pre class="programlisting">/* Open a database handle */ @@ -304,11 +305,11 @@ open_db(DB_ENV *envp, DB **dbpp, const char *file_name) </div> <p> In this section we provide the implementation of the - <code class="methodname">warm_cache()</code> function. This example - function simply loads all the database pages that will fit into - the memory pool. It starts from the first database page and - continues until it either runs out of database pages or it runs - out of room in the memory pool. + <code class="methodname">warm_cache()</code> function. This + example function simply loads all the database pages that + will fit into the memory pool. It starts from the first + database page and continues until it either runs out of + database pages or it runs out of room in the memory pool. </p> <a id="prog_mp01-7"></a> <pre class="programlisting">/* Warm the cache */ @@ -378,9 +379,7 @@ warm_cache(DB *dbp, int *pagecountp, int numcachepages) <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> - <td width="40%" align="right" valign="top"> Chapter 19. - The Transaction Subsystem - </td> + <td width="40%" align="right" valign="top"> Chapter 19. The Transaction Subsystem </td> </tr> </table> </div> |