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Diffstat (limited to 'lib/erl_interface/doc/src/registry.xml')
| -rw-r--r-- | lib/erl_interface/doc/src/registry.xml | 617 |
1 files changed, 308 insertions, 309 deletions
diff --git a/lib/erl_interface/doc/src/registry.xml b/lib/erl_interface/doc/src/registry.xml index 285a2402b8..fd3e29c30f 100644 --- a/lib/erl_interface/doc/src/registry.xml +++ b/lib/erl_interface/doc/src/registry.xml @@ -11,7 +11,7 @@ Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at - + http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software @@ -19,7 +19,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. - + </legalnotice> <title>registry</title> @@ -30,10 +30,10 @@ <checked>Gordon Beaton</checked> <date>980707</date> <rev>A</rev> - <file>registry.sgml</file> + <file>registry.xml</file> </header> <lib>registry</lib> - <libsummary>Store and backup key-value pairs</libsummary> + <libsummary>Store and backup key-value pairs.</libsummary> <description> <p>This module provides support for storing key-value pairs in a table known as a registry, backing up registries to @@ -42,51 +42,8 @@ </description> <funcs> <func> - <name><ret>ei_reg *</ret><nametext>ei_reg_open(size)</nametext></name> - <fsummary>Create and open a registry</fsummary> - <type> - <v>int size;</v> - </type> - <desc> - <p>Open (create) a registry. The registry will be - initially empty. Use <c><![CDATA[ei_reg_close()]]></c> to close the registry - later. - </p> - <p><c><![CDATA[size]]></c> is the approximate number of objects you intend - to store in the registry. Since the registry uses a hash table - with collision chaining, there is no absolute upper limit on the - number of objects that can be stored in it. However for reasons - of efficiency, it is a good idea to choose a number that is - appropriate for your needs. It is possible to use - <c><![CDATA[ei_reg_resize()]]></c> to change the size later. Note that the - number you provide will be increased to the nearest larger prime - number. - </p> - <p>On success, an empty registry will be returned. On failure, NULL - will be returned.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_reg_resize(reg,newsize)</nametext></name> - <fsummary>Resize a registry</fsummary> - <type> - <v>ei_reg *reg;</v> - <v>int newsize;</v> - </type> - <desc> - <p>Change the size of a registry. - </p> - <p><c><![CDATA[newsize]]></c> is the new size to make the registry. The - number will be increased to the nearest larger prime number. - </p> - <p>On success, the registry will be resized, all contents - rehashed, and the function will return 0. On failure, the - registry will be left unchanged and the function will return -1.</p> - </desc> - </func> - <func> <name><ret>int</ret><nametext>ei_reg_close(reg)</nametext></name> - <fsummary>Close a registry </fsummary> + <fsummary>Close a registry.</fsummary> <type> <v>ei_reg *reg;</v> </type> @@ -101,153 +58,83 @@ </desc> </func> <func> - <name><ret>int</ret><nametext>ei_reg_setival(reg,key,i)</nametext></name> - <fsummary>Assign an integer object</fsummary> - <type> - <v>ei_reg *reg;</v> - <v>const char *key;</v> - <v>int i;</v> - </type> - <desc> - <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> and integer - value <c><![CDATA[i]]></c>. If an object already existed with the same - <c><![CDATA[key]]></c>, the new value replaces the old one. If the previous - value was a binary or string, it is freed with <c><![CDATA[free()]]></c>. - </p> - <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. - </p> - <p><c><![CDATA[key]]></c> is the name of the object. - </p> - <p><c><![CDATA[i]]></c> is the integer value to assign. - </p> - <p>The function returns 0 on success, or -1 on failure.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_reg_setfval(reg,key,f)</nametext></name> - <fsummary>Assign a floating point object</fsummary> - <type> - <v>ei_reg *reg;</v> - <v>const char *key;</v> - <v>double f;</v> - </type> - <desc> - <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> and - floating point value <c><![CDATA[f]]></c>. If an object already existed with - the same <c><![CDATA[key]]></c>, the new value replaces the old one. If the - previous value was a binary or string, it is freed with <c><![CDATA[free()]]></c>. - </p> - <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. - </p> - <p><c><![CDATA[key]]></c> is the name of the object. - </p> - <p><c><![CDATA[f]]></c> is the floating point value to assign. - </p> - <p>The function returns 0 on success, or -1 on failure.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_reg_setsval(reg,key,s)</nametext></name> - <fsummary>Assign a string object</fsummary> - <type> - <v>ei_reg *reg;</v> - <v>const char *key;</v> - <v>const char *s;</v> - </type> - <desc> - <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> whose - "value" is the specified string <c><![CDATA[s]]></c>. If an object already - existed with the same <c><![CDATA[key]]></c>, the new value replaces the old - one. If the previous value was a binary or string, it is freed - with <c><![CDATA[free()]]></c>. - </p> - <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. - </p> - <p><c><![CDATA[key]]></c> is the name of the object. - </p> - <p><c><![CDATA[s]]></c> is the string to assign. The string itself - must have been created through a single call to <c><![CDATA[malloc()]]></c> or - similar function, so that the registry can later delete it if - necessary by calling <c><![CDATA[free()]]></c>. - </p> - <p>The function returns 0 on success, or -1 on failure.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_reg_setpval(reg,key,p,size)</nametext></name> - <fsummary>Assign a binary object</fsummary> + <name><ret>int</ret><nametext>ei_reg_delete(reg,key)</nametext></name> + <fsummary>Delete an object from the registry.</fsummary> <type> <v>ei_reg *reg;</v> <v>const char *key;</v> - <v>const void *p;</v> - <v>int size;</v> </type> <desc> - <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> whose - "value" is the binary object pointed to by <c><![CDATA[p]]></c>. If an - object already existed with the same <c><![CDATA[key]]></c>, the new value - replaces the old one. If the previous value was a binary or - string, it is freed with <c><![CDATA[free()]]></c>. - </p> - <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. + <p>Delete an object from the registry. The object is not + actually removed from the registry, it is only marked for later + removal so that on subsequent backups to Mnesia, the + corresponding object can be removed from the Mnesia table as + well. If another object is later created with the same key, the + object will be reused. </p> - <p><c><![CDATA[key]]></c> is the name of the object. + <p>The object will be removed from the registry after a call to + <c><![CDATA[ei_reg_dump()]]></c> or <c><![CDATA[ei_reg_purge()]]></c>. </p> - <p><c><![CDATA[p]]></c> is a pointer to the binary object. The object itself - must have been created through a single call to <c><![CDATA[malloc()]]></c> or - similar function, so that the registry can later delete it if - necessary by calling <c><![CDATA[free()]]></c>. + <p><c><![CDATA[reg]]></c> is the registry containing <c><![CDATA[key]]></c>. </p> - <p><c><![CDATA[size]]></c> is the length in bytes of the binary object. + <p><c><![CDATA[key]]></c> is the object to remove. </p> - <p>The function returns 0 on success, or -1 on failure.</p> + <p>If the object was found, the function returns 0 indicating + success. Otherwise the function returns -1.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_reg_setval(reg,key,flags,v,...)</nametext></name> - <fsummary>Assign a value to any object type</fsummary> + <name><ret>int</ret><nametext>ei_reg_dump(fd,reg,mntab,flags)</nametext></name> + <fsummary>Back up a registry to Mnesia.</fsummary> <type> + <v>int fd;</v> <v>ei_reg *reg;</v> - <v>const char *key;</v> + <v>const char *mntab;</v> <v>int flags;</v> - <v>v (see below)</v> </type> <desc> - <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> whose - value is specified by <c><![CDATA[v]]></c>. If an object already - existed with the same <c><![CDATA[key]]></c>, the new value replaces the old - one. If the previous value was a binary or string, it is freed - with <c><![CDATA[free()]]></c>. + <p>Dump the contents of a registry to a Mnesia table in an + atomic manner, i.e. either all data will be updated, or none of + it will. If any errors are encountered while backing up + the data, the entire operation is aborted. </p> - <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. + <p><c><![CDATA[fd]]></c> is an open connection to Erlang. + Mnesia 3.0 or later must be running on the Erlang node. </p> - <p><c><![CDATA[key]]></c> is the name of the object. + <p><c><![CDATA[reg]]></c> is the registry to back up. </p> - <p><c><![CDATA[flags]]></c> indicates the type of the object specified by - <c><![CDATA[v]]></c>. Flags must be one of EI_INT, EI_FLT, EI_STR and - EI_BIN, indicating whether <c><![CDATA[v]]></c> is <c><![CDATA[int]]></c>, <c><![CDATA[double]]></c>, - <c><![CDATA[char*]]></c> or <c><![CDATA[void*]]></c>. If <c><![CDATA[flags]]></c> is EI_BIN, then a - fifth argument <c><![CDATA[size]]></c> is required, indicating the size - in bytes of the object pointed to by <c><![CDATA[v]]></c>. + <p><c><![CDATA[mntab]]></c> is the name of the Mnesia table where the backed + up data should be placed. If the table does not exist, it will + be created automatically using configurable defaults. See your + Mnesia documentation for information about configuring this + behaviour. </p> - <p>If you wish to store an arbitrary pointer in the registry, - specify a <c><![CDATA[size]]></c> of 0. In this case, the object itself will - not be transferred by an <c><![CDATA[ei_reg_dump()]]></c> operation, just - the pointer value. + <p>If <c><![CDATA[flags]]></c> is 0, the backup will include only those + objects which have been created, modified or deleted since the + last backup or restore (i.e. an incremental backup). After the + backup, any objects that were marked dirty are now clean, and any + objects that had been marked for deletion are deleted. + </p> + <p>Alternatively, setting flags to EI_FORCE will cause a full + backup to be done, and EI_NOPURGE will cause the deleted objects + to be left in the registry afterwards. These can be bitwise ORed + together if both behaviours are desired. If EI_NOPURGE was + specified, you can use <c><![CDATA[ei_reg_purge()]]></c> to explicitly remove + the deleted items from the registry later. </p> <p>The function returns 0 on success, or -1 on failure.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_reg_getival(reg,key)</nametext></name> - <fsummary>Get an integer object</fsummary> + <name><ret>double</ret><nametext>ei_reg_getfval(reg,key)</nametext></name> + <fsummary>Get a floating point object.</fsummary> <type> <v>ei_reg *reg;</v> <v>const char *key;</v> </type> <desc> <p>Get the value associated with <c><![CDATA[key]]></c> in the - registry. The value must be an integer. + registry. The value must be a floating point type. </p> <p><c><![CDATA[reg]]></c> is the registry where the object will be looked up. @@ -255,23 +142,23 @@ <p><c><![CDATA[key]]></c> is the name of the object to look up. </p> <p>On success, the function returns the value associated with <c><![CDATA[key]]></c>. - If the object was not found or it was not an integer - object, -1 is returned. To avoid problems with in-band error - reporting (i.e. if you cannot distinguish between -1 and a + If the object was not found or it was not a floating point + object, -1.0 is returned. To avoid problems with in-band error + reporting (i.e. if you cannot distinguish between -1.0 and a valid result) use the more general function <c><![CDATA[ei_reg_getval()]]></c> instead.</p> </desc> </func> <func> - <name><ret>double</ret><nametext>ei_reg_getfval(reg,key)</nametext></name> - <fsummary>Get a floating point object</fsummary> + <name><ret>int</ret><nametext>ei_reg_getival(reg,key)</nametext></name> + <fsummary>Get an integer object.</fsummary> <type> <v>ei_reg *reg;</v> <v>const char *key;</v> </type> <desc> <p>Get the value associated with <c><![CDATA[key]]></c> in the - registry. The value must be a floating point type. + registry. The value must be an integer. </p> <p><c><![CDATA[reg]]></c> is the registry where the object will be looked up. @@ -279,31 +166,36 @@ <p><c><![CDATA[key]]></c> is the name of the object to look up. </p> <p>On success, the function returns the value associated with <c><![CDATA[key]]></c>. - If the object was not found or it was not a floating point - object, -1.0 is returned. To avoid problems with in-band error - reporting (i.e. if you cannot distinguish between -1.0 and a + If the object was not found or it was not an integer + object, -1 is returned. To avoid problems with in-band error + reporting (i.e. if you cannot distinguish between -1 and a valid result) use the more general function <c><![CDATA[ei_reg_getval()]]></c> instead.</p> </desc> </func> <func> - <name><ret>const char *</ret><nametext>ei_reg_getsval(reg,key)</nametext></name> - <fsummary>Get a string object</fsummary> + <name><ret>const void *</ret><nametext>ei_reg_getpval(reg,key,size)</nametext></name> + <fsummary>Get a binary object.</fsummary> <type> <v>ei_reg *reg;</v> <v>const char *key;</v> + <v>int size;</v> </type> <desc> <p>Get the value associated with <c><![CDATA[key]]></c> in the - registry. The value must be a string. + registry. The value must be a binary (pointer) type. </p> <p><c><![CDATA[reg]]></c> is the registry where the object will be looked up. </p> <p><c><![CDATA[key]]></c> is the name of the object to look up. </p> + <p><c><![CDATA[size]]></c> will be initialized to contain the length in + bytes of the object, if it is found. + </p> <p>On success, the function returns the value associated with - <c><![CDATA[key]]></c>. If the object was not found or it was not a string, + <c><![CDATA[key]]></c> and indicates its length in <c><![CDATA[size]]></c>. + If the object was not found or it was not a binary object, NULL is returned. To avoid problems with in-band error reporting (i.e. if you cannot distinguish between NULL and a valid result) use the more general function <c><![CDATA[ei_reg_getval()]]></c> @@ -311,28 +203,23 @@ </desc> </func> <func> - <name><ret>const void *</ret><nametext>ei_reg_getpval(reg,key,size)</nametext></name> - <fsummary>Get a binary object</fsummary> + <name><ret>const char *</ret><nametext>ei_reg_getsval(reg,key)</nametext></name> + <fsummary>Get a string object.</fsummary> <type> <v>ei_reg *reg;</v> <v>const char *key;</v> - <v>int size;</v> </type> <desc> <p>Get the value associated with <c><![CDATA[key]]></c> in the - registry. The value must be a binary (pointer) type. + registry. The value must be a string. </p> <p><c><![CDATA[reg]]></c> is the registry where the object will be looked up. </p> <p><c><![CDATA[key]]></c> is the name of the object to look up. </p> - <p><c><![CDATA[size]]></c> will be initialized to contain the length in - bytes of the object, if it is found. - </p> <p>On success, the function returns the value associated with - <c><![CDATA[key]]></c> and indicates its length in <c><![CDATA[size]]></c>. - If the object was not found or it was not a binary object, + <c><![CDATA[key]]></c>. If the object was not found or it was not a string, NULL is returned. To avoid problems with in-band error reporting (i.e. if you cannot distinguish between NULL and a valid result) use the more general function <c><![CDATA[ei_reg_getval()]]></c> @@ -341,7 +228,7 @@ </func> <func> <name><ret>int</ret><nametext>ei_reg_getval(reg,key,flags,v,...)</nametext></name> - <fsummary>Get any object</fsummary> + <fsummary>Get any object.</fsummary> <type> <v>ei_reg *reg;</v> <v>const char *key;</v> @@ -350,7 +237,7 @@ </type> <desc> <p>This is a general function for retrieving any kind of - object from the registry. + object from the registry. </p> <p><c><![CDATA[reg]]></c> is the registry where the object will be looked up. @@ -376,7 +263,7 @@ </func> <func> <name><ret>int</ret><nametext>ei_reg_markdirty(reg,key)</nametext></name> - <fsummary>Mark an object as dirty </fsummary> + <fsummary>Mark an object as dirty.</fsummary> <type> <v>ei_reg *reg;</v> <v>const char *key;</v> @@ -390,7 +277,7 @@ registry and modified the contents, then the change will be invisible to the registry and the object will be assumed to be unmodified. This function allows you to make such modifications - and then let the registry know about them. + and then let the registry know about them. </p> <p><c><![CDATA[reg]]></c> is the registry containing the object. </p> @@ -400,34 +287,248 @@ </desc> </func> <func> - <name><ret>int</ret><nametext>ei_reg_delete(reg,key)</nametext></name> - <fsummary>Delete an object from the registry</fsummary> + <name><ret>ei_reg *</ret><nametext>ei_reg_open(size)</nametext></name> + <fsummary>Create and open a registry.</fsummary> + <type> + <v>int size;</v> + </type> + <desc> + <p>Open (create) a registry. The registry will be + initially empty. Use <c><![CDATA[ei_reg_close()]]></c> to close the registry + later. + </p> + <p><c><![CDATA[size]]></c> is the approximate number of objects you intend + to store in the registry. Since the registry uses a hash table + with collision chaining, there is no absolute upper limit on the + number of objects that can be stored in it. However for reasons + of efficiency, it is a good idea to choose a number that is + appropriate for your needs. It is possible to use + <c><![CDATA[ei_reg_resize()]]></c> to change the size later. Note that the + number you provide will be increased to the nearest larger prime + number. + </p> + <p>On success, an empty registry will be returned. On failure, NULL + will be returned.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_reg_purge(reg)</nametext></name> + <fsummary>Remove deleted objects.</fsummary> + <type> + <v>ei_reg *reg;</v> + </type> + <desc> + <p>Remove all objects marked for deletion. When objects + are deleted with <c><![CDATA[ei_reg_delete()]]></c> they are not actually + removed from the registry, only marked for later removal. This + is so that on a subsequent backup to Mnesia, the + objects can also be removed from the Mnesia table. If you are + not backing up to Mnesia then you may wish to remove the objects + manually with this function. + </p> + <p><c><![CDATA[reg]]></c> is a registry containing objects marked for + deletion. + </p> + <p>The function returns 0 on success, or -1 on failure.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_reg_resize(reg,newsize)</nametext></name> + <fsummary>Resize a registry.</fsummary> + <type> + <v>ei_reg *reg;</v> + <v>int newsize;</v> + </type> + <desc> + <p>Change the size of a registry. + </p> + <p><c><![CDATA[newsize]]></c> is the new size to make the registry. The + number will be increased to the nearest larger prime number. + </p> + <p>On success, the registry will be resized, all contents + rehashed, and the function will return 0. On failure, the + registry will be left unchanged and the function will return -1.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_reg_restore(fd,reg,mntab)</nametext></name> + <fsummary>Restore a registry from Mnesia.</fsummary> + <type> + <v>int fd;</v> + <v>ei_reg *reg;</v> + <v>const char *mntab;</v> + </type> + <desc> + <p>The contents of a Mnesia table are read into the + registry. + </p> + <p><c><![CDATA[fd]]></c> is an open connection to Erlang. + Mnesia 3.0 or later must be running on the Erlang node. + </p> + <p><c><![CDATA[reg]]></c> is the registry where the data should be placed. + </p> + <p><c><![CDATA[mntab]]></c> is the name of the Mnesia table to read data + from. + </p> + <p>Note that only tables of a certain format can be + restored, i.e. those that have been created and backed up to + with <c><![CDATA[ei_reg_dump()]]></c>. If the registry was not empty before + the operation, then the contents of the table are added to the + contents of the registry. If the table contains objects with the + same keys as those already in the registry, the registry objects + will be overwritten with the new values. If the registry + contains objects that were not in the table, they will be + unchanged by this operation. + </p> + <p>After the restore operation, the entire contents of the + registry is marked as unmodified. Note that this includes any + objects that were modified before the restore and not + overwritten by the restore. + </p> + <p>The function returns 0 on success, or -1 on failure.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_reg_setfval(reg,key,f)</nametext></name> + <fsummary>Assign a floating point object.</fsummary> <type> <v>ei_reg *reg;</v> <v>const char *key;</v> + <v>double f;</v> </type> <desc> - <p>Delete an object from the registry. The object is not - actually removed from the registry, it is only marked for later - removal so that on subsequent backups to Mnesia, the - corresponding object can be removed from the Mnesia table as - well. If another object is later created with the same key, the - object will be reused. + <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> and + floating point value <c><![CDATA[f]]></c>. If an object already existed with + the same <c><![CDATA[key]]></c>, the new value replaces the old one. If the + previous value was a binary or string, it is freed with <c><![CDATA[free()]]></c>. </p> - <p>The object will be removed from the registry after a call to - <c><![CDATA[ei_reg_dump()]]></c> or <c><![CDATA[ei_reg_purge()]]></c>. + <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. </p> - <p><c><![CDATA[reg]]></c> is the registry containing <c><![CDATA[key]]></c>. + <p><c><![CDATA[key]]></c> is the name of the object. </p> - <p><c><![CDATA[key]]></c> is the object to remove. + <p><c><![CDATA[f]]></c> is the floating point value to assign. </p> - <p>If the object was found, the function returns 0 indicating - success. Otherwise the function returns -1.</p> + <p>The function returns 0 on success, or -1 on failure.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_reg_setival(reg,key,i)</nametext></name> + <fsummary>Assign an integer object.</fsummary> + <type> + <v>ei_reg *reg;</v> + <v>const char *key;</v> + <v>int i;</v> + </type> + <desc> + <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> and integer + value <c><![CDATA[i]]></c>. If an object already existed with the same + <c><![CDATA[key]]></c>, the new value replaces the old one. If the previous + value was a binary or string, it is freed with <c><![CDATA[free()]]></c>. + </p> + <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. + </p> + <p><c><![CDATA[key]]></c> is the name of the object. + </p> + <p><c><![CDATA[i]]></c> is the integer value to assign. + </p> + <p>The function returns 0 on success, or -1 on failure.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_reg_setpval(reg,key,p,size)</nametext></name> + <fsummary>Assign a binary object.</fsummary> + <type> + <v>ei_reg *reg;</v> + <v>const char *key;</v> + <v>const void *p;</v> + <v>int size;</v> + </type> + <desc> + <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> whose + "value" is the binary object pointed to by <c><![CDATA[p]]></c>. If an + object already existed with the same <c><![CDATA[key]]></c>, the new value + replaces the old one. If the previous value was a binary or + string, it is freed with <c><![CDATA[free()]]></c>. + </p> + <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. + </p> + <p><c><![CDATA[key]]></c> is the name of the object. + </p> + <p><c><![CDATA[p]]></c> is a pointer to the binary object. The object itself + must have been created through a single call to <c><![CDATA[malloc()]]></c> or + similar function, so that the registry can later delete it if + necessary by calling <c><![CDATA[free()]]></c>. + </p> + <p><c><![CDATA[size]]></c> is the length in bytes of the binary object. + </p> + <p>The function returns 0 on success, or -1 on failure.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_reg_setsval(reg,key,s)</nametext></name> + <fsummary>Assign a string object.</fsummary> + <type> + <v>ei_reg *reg;</v> + <v>const char *key;</v> + <v>const char *s;</v> + </type> + <desc> + <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> whose + "value" is the specified string <c><![CDATA[s]]></c>. If an object already + existed with the same <c><![CDATA[key]]></c>, the new value replaces the old + one. If the previous value was a binary or string, it is freed + with <c><![CDATA[free()]]></c>. + </p> + <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. + </p> + <p><c><![CDATA[key]]></c> is the name of the object. + </p> + <p><c><![CDATA[s]]></c> is the string to assign. The string itself + must have been created through a single call to <c><![CDATA[malloc()]]></c> or + similar function, so that the registry can later delete it if + necessary by calling <c><![CDATA[free()]]></c>. + </p> + <p>The function returns 0 on success, or -1 on failure.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_reg_setval(reg,key,flags,v,...)</nametext></name> + <fsummary>Assign a value to any object type.</fsummary> + <type> + <v>ei_reg *reg;</v> + <v>const char *key;</v> + <v>int flags;</v> + <v>v (see below)</v> + </type> + <desc> + <p>Create a key-value pair with the specified <c><![CDATA[key]]></c> whose + value is specified by <c><![CDATA[v]]></c>. If an object already + existed with the same <c><![CDATA[key]]></c>, the new value replaces the old + one. If the previous value was a binary or string, it is freed + with <c><![CDATA[free()]]></c>. + </p> + <p><c><![CDATA[reg]]></c> is the registry where the object should be placed. + </p> + <p><c><![CDATA[key]]></c> is the name of the object. + </p> + <p><c><![CDATA[flags]]></c> indicates the type of the object specified by + <c><![CDATA[v]]></c>. Flags must be one of EI_INT, EI_FLT, EI_STR and + EI_BIN, indicating whether <c><![CDATA[v]]></c> is <c><![CDATA[int]]></c>, <c><![CDATA[double]]></c>, + <c><![CDATA[char*]]></c> or <c><![CDATA[void*]]></c>. If <c><![CDATA[flags]]></c> is EI_BIN, then a + fifth argument <c><![CDATA[size]]></c> is required, indicating the size + in bytes of the object pointed to by <c><![CDATA[v]]></c>. + </p> + <p>If you wish to store an arbitrary pointer in the registry, + specify a <c><![CDATA[size]]></c> of 0. In this case, the object itself will + not be transferred by an <c><![CDATA[ei_reg_dump()]]></c> operation, just + the pointer value. + </p> + <p>The function returns 0 on success, or -1 on failure.</p> </desc> </func> <func> <name><ret>int</ret><nametext>ei_reg_stat(reg,key,obuf)</nametext></name> - <fsummary>Get object information</fsummary> + <fsummary>Get object information.</fsummary> <type> <v>ei_reg *reg;</v> <v>const char *key;</v> @@ -452,7 +553,7 @@ struct ei_reg_stat { <p>In <c><![CDATA[attr]]></c> the object's attributes are stored as the logical OR of its type (one of EI_INT, EI_FLT, EI_BIN and EI_STR), whether it is marked for deletion (EI_DELET) and whether it has - been modified since the last backup to Mnesia (EI_DIRTY). + been modified since the last backup to Mnesia (EI_DIRTY). </p> <p>The <c><![CDATA[size]]></c> field indicates the size in bytes required to store EI_STR (including the terminating 0) and EI_BIN objects, or 0 @@ -464,7 +565,7 @@ struct ei_reg_stat { </func> <func> <name><ret>int</ret><nametext>ei_reg_tabstat(reg,obuf)</nametext></name> - <fsummary>Get registry information</fsummary> + <fsummary>Get registry information.</fsummary> <type> <v>ei_reg *reg;</v> <v>struct ei_reg_tabstat *obuf;</v> @@ -496,7 +597,7 @@ struct ei_reg_tabstat { registry. It includes objects that are deleted but not purged. </p> <p><c><![CDATA[npos]]></c> indicates the number of unique positions that are - occupied in the registry. + occupied in the registry. </p> <p><c><![CDATA[collisions]]></c> indicates how many elements are sharing positions in the registry. @@ -506,107 +607,5 @@ struct ei_reg_tabstat { returns -1.</p> </desc> </func> - <func> - <name><ret>int</ret><nametext>ei_reg_dump(fd,reg,mntab,flags)</nametext></name> - <fsummary>Back up a registry to Mnesia</fsummary> - <type> - <v>int fd;</v> - <v>ei_reg *reg;</v> - <v>const char *mntab;</v> - <v>int flags;</v> - </type> - <desc> - <p>Dump the contents of a registry to a Mnesia table in an - atomic manner, i.e. either all data will be updated, or none of - it will. If any errors are encountered while backing up - the data, the entire operation is aborted. - </p> - <p><c><![CDATA[fd]]></c> is an open connection to Erlang. - Mnesia 3.0 or later must be running on the Erlang node. - </p> - <p><c><![CDATA[reg]]></c> is the registry to back up. - </p> - <p><c><![CDATA[mntab]]></c> is the name of the Mnesia table where the backed - up data should be placed. If the table does not exist, it will - be created automatically using configurable defaults. See your - Mnesia documentation for information about configuring this - behaviour. - </p> - <p>If <c><![CDATA[flags]]></c> is 0, the backup will include only those - objects which have been created, modified or deleted since the - last backup or restore (i.e. an incremental backup). After the - backup, any objects that were marked dirty are now clean, and any - objects that had been marked for deletion are deleted. - </p> - <p>Alternatively, setting flags to EI_FORCE will cause a full - backup to be done, and EI_NOPURGE will cause the deleted objects - to be left in the registry afterwards. These can be bitwise ORed - together if both behaviours are desired. If EI_NOPURGE was - specified, you can use <c><![CDATA[ei_reg_purge()]]></c> to explicitly remove - the deleted items from the registry later. - </p> - <p>The function returns 0 on success, or -1 on failure.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_reg_restore(fd,reg,mntab)</nametext></name> - <fsummary>Restore a registry from Mnesia</fsummary> - <type> - <v>int fd;</v> - <v>ei_reg *reg;</v> - <v>const char *mntab;</v> - </type> - <desc> - <p>The contents of a Mnesia table are read into the - registry. - </p> - <p><c><![CDATA[fd]]></c> is an open connection to Erlang. - Mnesia 3.0 or later must be running on the Erlang node. - </p> - <p><c><![CDATA[reg]]></c> is the registry where the data should be placed. - </p> - <p><c><![CDATA[mntab]]></c> is the name of the Mnesia table to read data - from. - </p> - <p>Note that only tables of a certain format can be - restored, i.e. those that have been created and backed up to - with <c><![CDATA[ei_reg_dump()]]></c>. If the registry was not empty before - the operation, then the contents of the table are added to the - contents of the registry. If the table contains objects with the - same keys as those already in the registry, the registry objects - will be overwritten with the new values. If the registry - contains objects that were not in the table, they will be - unchanged by this operation. - </p> - <p>After the restore operation, the entire contents of the - registry is marked as unmodified. Note that this includes any - objects that were modified before the restore and not - overwritten by the restore. - </p> - <p>The function returns 0 on success, or -1 on failure.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_reg_purge(reg)</nametext></name> - <fsummary>Remove deleted objects</fsummary> - <type> - <v>ei_reg *reg;</v> - </type> - <desc> - <p>Remove all objects marked for deletion. When objects - are deleted with <c><![CDATA[ei_reg_delete()]]></c> they are not actually - removed from the registry, only marked for later removal. This - is so that on a subsequent backup to Mnesia, the - objects can also be removed from the Mnesia table. If you are - not backing up to Mnesia then you may wish to remove the objects - manually with this function. - </p> - <p><c><![CDATA[reg]]></c> is a registry containing objects marked for - deletion. - </p> - <p>The function returns 0 on success, or -1 on failure.</p> - </desc> - </func> </funcs> </cref> - |