/*
* Copyright 2019 the Pacemaker project contributors
*
* The version control history for this file may have further details.
*
* This source code is licensed under the GNU Lesser General Public License
* version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
*/
#ifndef CRM_OUTPUT__H
# define CRM_OUTPUT__H
#ifdef __cplusplus
extern "C" {
#endif
/**
* \file
* \brief Formatted output for pacemaker tools
*/
# include <stdbool.h>
# include <stdio.h>
# include <libxml/tree.h>
# include <libxml/HTMLtree.h>
# include <glib.h>
# include <crm/common/results.h>
# define PCMK__API_VERSION "2.0"
typedef struct pcmk__output_s pcmk__output_t;
/*!
* \internal
* \brief The type of a function that creates a ::pcmk__output_t.
*
* Instances of this type are passed to pcmk__register_format(), stored in an
* internal data structure, and later accessed by pcmk__output_new(). For
* examples, see pcmk__mk_xml_output() and pcmk__mk_text_output().
*
* \param[in] argv The list of command line arguments.
*/
typedef pcmk__output_t * (*pcmk__output_factory_t)(char **argv);
/*!
* \internal
* \brief The type of a custom message formatting function.
*
* These functions are defined by various libraries to support formatting of
* types aside from the basic types provided by a ::pcmk__output_t.
*
* The meaning of the return value will be different for each message.
* In general, however, 0 should be returned on success and a positive value
* on error.
*
* \note These functions must not call va_start or va_end - that is done
* automatically before the custom formatting function is called.
*/
typedef int (*pcmk__message_fn_t)(pcmk__output_t *out, va_list args);
/*!
* \internal
* \brief Internal type for tracking custom messages.
*
* Each library can register functions that format custom message types. These
* are commonly used to handle some library-specific type. Registration is
* done by first defining a table of ::pcmk__message_entry_t structures and
* then passing that table to pcmk__register_messages(). Separate handlers
* can be defined for the same message, but for different formats (xml vs.
* text). Unknown formats will be ignored.
*/
typedef struct pcmk__message_entry_s {
/*!
* \brief The message to be handled.
*
* This must be the same ID that is passed to the message function of
* a ::pcmk__output_t. Unknown message IDs will be ignored.
*/
const char *message_id;
/*!
* \brief The format type this handler is for.
*
* This name must match the fmt_name of the currently active formatter in
* order for the registered function to be called. It is valid to have
* multiple entries for the same message_id but with different fmt_name
* values.
*/
const char *fmt_name;
/*!
* \brief The function to be called for message_id given a match on
* fmt_name. See comments on ::pcmk__message_fn_t.
*/
pcmk__message_fn_t fn;
} pcmk__message_entry_t;
/*!
* \internal
* \brief This structure contains everything needed to add support for a
* single output formatter to a command line program.
*/
typedef struct pcmk__supported_format_s {
/*!
* \brief The name of this output formatter, which should match the
* fmt_name parameter in some ::pcmk__output_t structure.
*/
const char *name;
/*!
* \brief A function that creates a ::pcmk__output_t.
*/
pcmk__output_factory_t create;
/*!
* \brief Format-specific command line options. This can be NULL if
* no command line options should be supported.
*/
GOptionEntry *options;
} pcmk__supported_format_t;
/* The following three blocks need to be updated each time a new base formatter
* is added.
*/
extern GOptionEntry pcmk__html_output_entries[];
extern GOptionEntry pcmk__none_output_entries[];
extern GOptionEntry pcmk__text_output_entries[];
extern GOptionEntry pcmk__xml_output_entries[];
pcmk__output_t *pcmk__mk_html_output(char **argv);
pcmk__output_t *pcmk__mk_none_output(char **argv);
pcmk__output_t *pcmk__mk_text_output(char **argv);
pcmk__output_t *pcmk__mk_xml_output(char **argv);
#define PCMK__SUPPORTED_FORMAT_HTML { "html", pcmk__mk_html_output, pcmk__html_output_entries }
#define PCMK__SUPPORTED_FORMAT_NONE { "none", pcmk__mk_none_output, pcmk__none_output_entries }
#define PCMK__SUPPORTED_FORMAT_TEXT { "text", pcmk__mk_text_output, pcmk__text_output_entries }
#define PCMK__SUPPORTED_FORMAT_XML { "xml", pcmk__mk_xml_output, pcmk__xml_output_entries }
/*!
* \brief This structure contains everything that makes up a single output
* formatter.
*
* Instances of this structure may be created by calling pcmk__output_new()
* with the name of the desired formatter. They should later be freed with
* pcmk__output_free().
*/
struct pcmk__output_s {
/*!
* \brief The name of this output formatter.
*/
const char *fmt_name;
/*!
* \brief A copy of the request that generated this output.
*
* In the case of command line usage, this would be the command line
* arguments. For other use cases, it could be different.
*/
char *request;
/*!
* \brief Does this formatter support a special quiet mode?
*
* In this mode, most output can be supressed but some information is still
* displayed to an interactive user. In general, machine-readable output
* formats will not support this while user-oriented formats will.
*/
bool supports_quiet;
/*!
* \brief Where output should be written.
*
* This could be a file handle, or stdout or stderr. This is really only
* useful internally.
*/
FILE *dest;
/*!
* \brief Custom messages that are currently registered on this formatter.
*
* Keys are the string message IDs, values are ::pcmk__message_fn_t function
* pointers.
*/
GHashTable *messages;
/*!
* \brief Implementation-specific private data.
*
* Each individual formatter may have some private data useful in its
* implementation. This points to that data. Callers should not rely on
* its contents or structure.
*/
void *priv;
/*!
* \internal
* \brief Take whatever actions are necessary to prepare out for use. This is
* called by pcmk__output_new(). End users should not need to call this.
*
* \note For formatted output implementers - This function should be written in
* such a way that it can be called repeatedly on an already initialized
* object without causing problems, or on a previously finished object
* without crashing.
*
* \param[in,out] out The output functions structure.
*
* \return true on success, false on error.
*/
bool (*init) (pcmk__output_t *out);
/*!
* \internal
* \brief Free the private formatter-specific data.
*
* This is called from pcmk__output_free() and does not typically need to be
* called directly.
*
* \param[in,out] out The output functions structure.
*/
void (*free_priv)(pcmk__output_t *out);
/*!
* \internal
* \brief Take whatever actions are necessary to end formatted output.
*
* This could include flushing output to a file, but does not include freeing
* anything. The finish method can potentially be fairly complicated, adding
* additional information to the internal data structures or doing whatever
* else. It is therefore suggested that finish only be called once.
*
* \note The print parameter will only affect those formatters that do all
* their output at the end. Console-oriented formatters typically print
* a line at a time as they go, so this parameter will not affect them.
* Structured formatters will honor it, however.
*
* \note The copy_dest parameter does not apply to all formatters. Console-
* oriented formatters do not build up a structure as they go, and thus
* do not have anything to return. Structured formatters will honor it,
* however. Note that each type of formatter will return a different
* type of value in this parameter. To use this parameter, call this
* function like so:
*
* \code
* xmlNode *dest = NULL;
* out->finish(out, exit_code, false, (void **) &dest);
* \endcode
*
* \param[in,out] out The output functions structure.
* \param[in] exit_status The exit value of the whole program.
* \param[in] print Whether this function should write any output.
* \param[out] copy_dest A destination to store a copy of the internal
* data structure for this output, or NULL if no
* copy is required. The caller should free this
* memory when done with it.
*/
void (*finish) (pcmk__output_t *out, crm_exit_t exit_status, bool print,
void **copy_dest);
/*!
* \internal
* \brief Finalize output and then immediately set back up to start a new set
* of output.
*
* This is conceptually the same as calling finish and then init, though in
* practice more be happening behind the scenes.
*
* \note This function differs from finish in that no exit_status is added.
* The idea is that the program is not shutting down, so there is not
* yet a final exit code. Call finish on the last time through if this
* is needed.
*
* \param[in,out] out The output functions structure.
*/
void (*reset) (pcmk__output_t *out);
/*!
* \internal
* \brief Register a custom message.
*
* \param[in,out] out The output functions structure.
* \param[in] message_id The name of the message to register. This name
* will be used as the message_id parameter to the
* message function in order to call the custom
* format function.
* \param[in] fn The custom format function to call for message_id.
*/
void (*register_message) (pcmk__output_t *out, const char *message_id,
pcmk__message_fn_t fn);
/*!
* \internal
* \brief Call a previously registered custom message.
*
* \param[in,out] out The output functions structure.
* \param[in] message_id The name of the message to call. This name must
* be the same as the message_id parameter of some
* previous call to register_message.
* \param[in] ... Arguments to be passed to the registered function.
*
* \return 0 if a function was registered for the message, that function was
* called, and returned successfully. A negative value is returned if
* no function was registered. A positive value is returned if the
* function was called but encountered an error.
*/
int (*message) (pcmk__output_t *out, const char *message_id, ...);
/*!
* \internal
* \brief Format the output of a completed subprocess.
*
* \param[in,out] out The output functions structure.
* \param[in] exit_status The exit value of the subprocess.
* \param[in] proc_stdout stdout from the completed subprocess.
* \param[in] proc_stderr stderr from the completed subprocess.
*/
void (*subprocess_output) (pcmk__output_t *out, int exit_status,
const char *proc_stdout, const char *proc_stderr);
/*!
* \internal
* \brief Format version information. This is useful for the --version
* argument of command line tools.
*
* \param[in,out] out The output functions structure.
* \param[in] extended Add additional version information.
*/
void (*version) (pcmk__output_t *out, bool extended);
/*!
* \internal
* \brief Format an informational message that should be shown to
* to an interactive user. Not all formatters will do this.
*
* \note A newline will automatically be added to the end of the format
* string, so callers should not include a newline.
*
* \param[in,out] out The output functions structure.
* \param[in] buf The message to be printed.
* \param[in] ... Arguments to be formatted.
*/
void (*info) (pcmk__output_t *out, const char *format, ...) G_GNUC_PRINTF(2, 3);
/*!
* \internal
* \brief Format an error message that should be shown to an interactive
* user. Not all formatters will do this.
*
* \note A newline will automatically be added to the end of the format
* string, so callers should not include a newline.
*
* \param[in,out] out The output functions structure.
* \param[in] buf The message to be printed.
* \param[in] ... Arguments to be formatted.
*/
void (*err) (pcmk__output_t *out, const char *format, ...) G_GNUC_PRINTF(2, 3);
/*!
* \internal
* \brief Format already formatted XML.
*
* \param[in,out] out The output functions structure.
* \param[in] name A name to associate with the XML.
* \param[in] buf The XML in a string.
*/
void (*output_xml) (pcmk__output_t *out, const char *name, const char *buf);
/*!
* \internal
* \brief Start a new list of items.
*
* \note For text output, this corresponds to another level of indentation. For
* XML output, this corresponds to wrapping any following output in another
* layer of tags.
*
* \note If singular_noun and plural_noun are non-NULL, calling end_list will
* result in a summary being added.
*
* \param[in,out] out The output functions structure.
* \param[in] singular_noun When outputting the summary for a list with
* one item, the noun to use.
* \param[in] plural_noun When outputting the summary for a list with
* more than one item, the noun to use.
* \param[in] format The format string.
* \param[in] ... Arguments to be formatted.
*/
void (*begin_list) (pcmk__output_t *out, const char *singular_noun,
const char *plural_noun, const char *format, ...)
G_GNUC_PRINTF(4, 5);
/*!
* \internal
* \brief Format a single item in a list.
*
* \param[in,out] out The output functions structure.
* \param[in] name A name to associate with this item.
* \param[in] format The format string.
* \param[in] ... Arguments to be formatted.
*/
void (*list_item) (pcmk__output_t *out, const char *name, const char *format, ...)
G_GNUC_PRINTF(3, 4);
/*!
* \internal
* \brief Increment the internal counter of the current list's length.
*
* Typically, this counter is maintained behind the scenes as a side effect
* of calling list_item(). However, custom functions that maintain lists
* some other way will need to manage this counter manually. This is
* useful for implementing custom message functions and should not be
* needed otherwise.
*
* \param[in,out] out The output functions structure.
*/
void (*increment_list) (pcmk__output_t *out);
/*!
* \internal
* \brief Conclude a list.
*
* \note If begin_list was called with non-NULL for both the singular_noun
* and plural_noun arguments, this function will output a summary.
* Otherwise, no summary will be added.
*
* \param[in,out] out The output functions structure.
*/
void (*end_list) (pcmk__output_t *out);
};
/*!
* \internal
* \brief Call a formatting function for a previously registered message.
*
* \note This function is for implementing custom formatters. It should not
* be called directly. Instead, call out->message.
*
* \param[in,out] out The output functions structure.
* \param[in] message_id The message to be handled. Unknown messages
* will be ignored.
* \param[in] ... Arguments to be passed to the registered function.
*/
int
pcmk__call_message(pcmk__output_t *out, const char *message_id, ...);
/*!
* \internal
* \brief Free a ::pcmk__output_t structure that was previously created by
* pcmk__output_new().
*
* \note While the create and finish functions are designed in such a way that
* they can be called repeatedly, this function will completely free the
* memory of the object. Once this function has been called, producing
* more output requires starting over from pcmk__output_new().
*
* \param[in,out] out The output structure.
*/
void pcmk__output_free(pcmk__output_t *out);
/*!
* \internal
* \brief Create a new ::pcmk__output_t structure.
*
* \param[in,out] out The destination of the new ::pcmk__output_t.
* \param[in] fmt_name How should output be formatted?
* \param[in] filename Where should formatted output be written to? This
* can be a filename (which will be overwritten if it
* already exists), or NULL or "-" for stdout. For no
* output, pass a filename of "/dev/null".
* \param[in] argv The list of command line arguments.
*
* \return 0 on success or an error code on error.
*/
int pcmk__output_new(pcmk__output_t **out, const char *fmt_name,
const char *filename, char **argv);
/*!
* \internal
* \brief Register a new output formatter, making it available for use
* the same as a base formatter.
*
* \param[in,out] group A ::GOptionGroup that formatted output related command
* line arguments should be added to. This can be NULL
* for use outside of command line programs.
* \param[in] name The name of the format. This will be used to select a
* format from command line options and for displaying help.
* \param[in] create A function that creates a ::pcmk__output_t.
* \param[in] options Format-specific command line options. These will be
* added to the context. This argument can also be NULL.
*
* \return 0 on success or an error code on error.
*/
int
pcmk__register_format(GOptionGroup *group, const char *name,
pcmk__output_factory_t create, GOptionEntry *options);
/*!
* \internal
* \brief Register an entire table of output formatters at once.
*
* \param[in,out] group A ::GOptionGroup that formatted output related command
* line arguments should be added to. This can be NULL
* for use outside of command line programs.
* \param[in] table An array of ::pcmk__supported_format_t which should
* all be registered. This array must be NULL-terminated.
*
*/
void
pcmk__register_formats(GOptionGroup *group, pcmk__supported_format_t *table);
/*!
* \internal
* \brief Register a function to handle a custom message.
*
* \note This function is for implementing custom formatters. It should not
* be called directly. Instead, call out->register_message.
*
* \param[in,out] out The output functions structure.
* \param[in] message_id The message to be handled.
* \param[in] fn The custom format function to call for message_id.
*/
void
pcmk__register_message(pcmk__output_t *out, const char *message_id,
pcmk__message_fn_t fn);
/*!
* \internal
* \brief Register an entire table of custom formatting functions at once.
*
* This table can contain multiple formatting functions for the same message ID
* if they are for different format types.
*
* \param[in,out] out The output functions structure.
* \param[in] table An array of ::pcmk__message_entry_t values which should
* all be registered. This array must be NULL-terminated.
*/
void
pcmk__register_messages(pcmk__output_t *out, pcmk__message_entry_t *table);
/* Functions that are useful for implementing custom message formatters */
/*!
* \internal
* \brief A printf-like function.
*
* This function writes to out->dest and indents the text to the current level
* of the text formatter's nesting. This should be used when implementing
* custom message functions instead of printf.
*
* \param[in,out] out The output functions structure.
*/
void
pcmk__indented_printf(pcmk__output_t *out, const char *format, ...) G_GNUC_PRINTF(2, 3);
/*!
* \internal
* \brief A vprintf-like function.
*
* This function is like pcmk__indented_printf(), except it takes a va_list instead
* of a list of arguments. This should be used when implementing custom message
* functions instead of vprintf.
*
* \param[in,out] out The output functions structure.
* \param[in] format The format string.
* \param[in] args A list of arguments to apply to the format string.
*/
void
pcmk__indented_vprintf(pcmk__output_t *out, const char *format, va_list args) G_GNUC_PRINTF(2, 0);
/*!
* \internal
* \brief Create and return a new XML node with the given name, as a child of the
* current list parent. The new node is then added as the new list parent,
* meaning all subsequent nodes will be its children. This is used when
* implementing custom functions.
*
* \param[in,out] out The output functions structure.
* \param[in] name The name of the node to be created.
*/
xmlNodePtr
pcmk__output_xml_create_parent(pcmk__output_t *out, const char *name);
/*!
* \internal
* \brief Add the given node as a child of the current list parent. This is
* used when implementing custom message functions.
*
* \param[in,out] out The output functions structure.
* \param[in] node An XML node to be added as a child.
*/
void
pcmk__output_xml_add_node(pcmk__output_t *out, xmlNodePtr node);
/*!
* \internal
* \brief Create and return a new XML node with the given name, as a child of the
* current list parent. This is used when implementing custom functions.
*
* \param[in,out] out The output functions structure.
* \param[in] name The name of the node to be created.
*/
xmlNodePtr
pcmk__output_create_xml_node(pcmk__output_t *out, const char *name);
/*!
* \internal
* \brief Like pcmk__output_create_xml_node(), but add the given text content to the
* new node.
*
* \param[in,out] out The output functions structure.
* \param[in] name The name of the node to be created.
* \param[in] content The text content of the node.
*/
xmlNodePtr
pcmk__output_create_xml_text_node(pcmk__output_t *out, const char *name, const char *content);
/*!
* \internal
* \brief Push a parent XML node onto the stack. This is used when implementing
* custom message functions.
*
* The XML output formatter maintains an internal stack to keep track of which nodes
* are parents in order to build up the tree structure. This function can be used
* to temporarily push a new node onto the stack. After calling this function, any
* other formatting functions will have their nodes added as children of this new
* parent.
*
* \param[in,out] out The output functions structure.
* \param[in] node The node to be added/
*/
void
pcmk__output_xml_push_parent(pcmk__output_t *out, xmlNodePtr node);
/*!
* \internal
* \brief Pop a parent XML node onto the stack. This is used when implementing
* custom message functions.
*
* This function removes a parent node from the stack. See pcmk__xml_push_parent()
* for more details.
*
* \note Little checking is done with this function. Be sure you only pop parents
* that were previously pushed. In general, it is best to keep the code between
* push and pop simple.
*
* \param[in,out] out The output functions structure.
*/
void
pcmk__output_xml_pop_parent(pcmk__output_t *out);
/*!
* \internal
* \brief Peek a parent XML node onto the stack. This is used when implementing
* custom message functions.
*
* This function peeks a parent node on stack. See pcmk__xml_push_parent()
* for more details. It has no side-effect and can be called for an empty stack.
*
* \note Little checking is done with this function.
*
* \param[in,out] out The output functions structure.
*
* \return NULL if stack is empty, otherwise the parent of the stack.
*/
xmlNodePtr
pcmk__output_xml_peek_parent(pcmk__output_t *out);
/*!
* \internal
* \brief Create a new XML node consisting of the provided text inside an HTML
* element node of the given name.
*
* \param[in,out] out The output functions structure.
* \param[in] element_name The name of the new HTML element.
* \param[in] id The CSS ID selector to apply to this element.
* If NULL, no ID is added.
* \param[in] class_name The CSS class selector to apply to this element.
* If NULL, no class is added.
* \param[in] text The text content of the node.
*/
xmlNodePtr
pcmk__output_create_html_node(pcmk__output_t *out, const char *element_name, const char *id,
const char *class_name, const char *text);
/*!
* \internal
* \brief Add an HTML tag to the <head> section.
*
* The arguments after name are a NULL-terminated list of keys and values,
* all of which will be added as attributes to the given tag. For instance,
* the following code would generate the tag "<meta http-equiv='refresh' content='19'>":
*
* \code
* pcmk__html_add_header(parent, "meta", "http-equiv", "refresh", "content", "19", NULL);
* \endcode
*
* \param[in,out] parent The node that will be the parent of the new node.
* \param[in] name The HTML tag for the new node.
* \param[in] ... A NULL-terminated key/value list of attributes.
*/
void
pcmk__html_add_header(xmlNodePtr parent, const char *name, ...)
G_GNUC_NULL_TERMINATED;
#ifdef __cplusplus
}
#endif
#endif