diff options
Diffstat (limited to 'lib/kernel/doc/src/wrap_log_reader.xml')
-rw-r--r-- | lib/kernel/doc/src/wrap_log_reader.xml | 66 |
1 files changed, 30 insertions, 36 deletions
diff --git a/lib/kernel/doc/src/wrap_log_reader.xml b/lib/kernel/doc/src/wrap_log_reader.xml index 18664a029f..6cf480b532 100644 --- a/lib/kernel/doc/src/wrap_log_reader.xml +++ b/lib/kernel/doc/src/wrap_log_reader.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1998</year><year>2009</year> + <year>1998</year><year>2011</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -50,18 +50,20 @@ the called node, it is entirely up to the user to be sure that all items are read. </p> </description> + <datatypes> + <datatype> + <name name="continuation"/> + <desc><p>Continuation returned by + <c>open/1,2</c> or <c>chunk/1,2</c>.</p> + </desc> + </datatype> + </datatypes> <funcs> <func> - <name>chunk(Continuation)</name> - <name>chunk(Continuation, N) -> {Continuation2, Terms} | {Continuation2, Terms, Badbytes} | {Continuation2, eof} | {error, Reason}</name> + <name name="chunk" arity="1"/> + <name name="chunk" arity="2"/> <fsummary>Read a chunk of objects written to a wrap log.</fsummary> - <type> - <v>Continuation = continuation()</v> - <v>N = int() > 0 | infinity</v> - <v>Continuation2 = continuation()</v> - <v>Terms= [term()]</v> - <v>Badbytes = integer()</v> - </type> + <type name="chunk_ret"/> <desc> <p>This function makes it possible to efficiently read the terms which have been appended to a log. It minimises disk @@ -70,29 +72,29 @@ <p>The first time <c>chunk</c> is called an initial continuation returned from the <c>open/1</c>, <c>open/2</c> must be provided. </p> - <p>When <c>chunk/3</c> is called, <c>N</c> controls the + <p>When <c>chunk/3</c> is called, <c><anno>N</anno></c> controls the maximum number of terms that are read from the log in each chunk. Default is <c>infinity</c>, which means that all the terms contained in the 8K chunk are read. If less than - <c>N</c> terms are returned, this does not necessarily mean + <c><anno>N</anno></c> terms are returned, this does not necessarily mean that end of file is reached. </p> <p>The <c>chunk</c> function returns a tuple - <c>{Continuation2, Terms}</c>, where <c>Terms</c> is a list - of terms found in the log. <c>Continuation2</c> is yet + <c>{<anno>Continuation2</anno>, <anno>Terms</anno>}</c>, where <c><anno>Terms</anno></c> is a list + of terms found in the log. <c><anno>Continuation2</anno></c> is yet another continuation which must be passed on into any subsequent calls to <c>chunk</c>. With a series of calls to <c>chunk</c> it is then possible to extract all terms from a log. </p> <p>The <c>chunk</c> function returns a tuple - <c>{Continuation2, Terms, Badbytes}</c> if the log is opened - in read only mode and the read chunk is corrupt. <c>Badbytes</c> + <c>{<anno>Continuation2</anno>, <anno>Terms</anno>, <anno>Badbytes</anno>}</c> if the log is opened + in read only mode and the read chunk is corrupt. <c><anno>Badbytes</anno></c> indicates the number of non-Erlang terms found in the chunk. Note also that the log is not repaired. </p> - <p><c>chunk</c> returns <c>{Continuation2, eof}</c> when the end of the log is - reached, and <c>{error, Reason}</c> if an error occurs. + <p><c>chunk</c> returns <c>{<anno>Continuation2</anno>, eof}</c> when the end of the log is + reached, and <c>{error, <anno>Reason</anno>}</c> if an error occurs. </p> <p>The returned continuation may or may not be valid in the next call to <c>chunk</c>. This is because the log may wrap and delete @@ -103,37 +105,29 @@ </desc> </func> <func> - <name>close(Continuation) -> ok </name> + <name name="close" arity="1"/> <fsummary>Close a log</fsummary> - <type> - <v>Continuation = continuation()</v> - </type> <desc> <p>This function closes a log file properly. </p> </desc> </func> <func> - <name>open(Filename) -> OpenRet</name> - <name>open(Filename, N) -> OpenRet</name> + <name name="open" arity="1"/> + <name name="open" arity="2"/> <fsummary>Open a log file</fsummary> - <type> - <v>File = string() | atom()</v> - <v>N = integer()</v> - <v>OpenRet = {ok, Continuation} | {error, Reason} </v> - <v>Continuation = continuation()</v> - </type> + <type name="open_ret"/> <desc> - <p><c>Filename</c> specifies the name of the file which is to be read. </p> - <p><c>N</c> specifies the index of the file which is to be read. - If <c>N</c> is omitted the whole wrap log file will be read; if it + <p><c><anno>Filename</anno></c> specifies the name of the file which is to be read. </p> + <p><c><anno>N</anno></c> specifies the index of the file which is to be read. + If <c><anno>N</anno></c> is omitted the whole wrap log file will be read; if it is specified only the specified index file will be read. </p> - <p>The <c>open</c> function returns <c>{ok, Continuation}</c> if the - log/index file was successfully opened. The <c>Continuation</c> + <p>The <c>open</c> function returns <c>{ok, <anno>Continuation</anno>}</c> if the + log/index file was successfully opened. The <c><anno>Continuation</anno></c> is to be used when chunking or closing the file. </p> - <p>The function returns <c>{error, Reason}</c> for all errors. + <p>The function returns <c>{error, <anno>Reason</anno>}</c> for all errors. </p> </desc> </func> |