From: Florian Forster Date: Wed, 21 Jul 2010 14:23:25 +0000 (+0200) Subject: src/graph_list.c: A first take at a JSON parser for reading back the cache file. X-Git-Tag: v4.0.0~76 X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=99f31aafefdd00b788d9ab2ba74b1cfb70c679e3;p=collection4.git src/graph_list.c: A first take at a JSON parser for reading back the cache file. It's UNTESTED! --- diff --git a/src/graph_list.c b/src/graph_list.c index 26e182b..2112c76 100644 --- a/src/graph_list.c +++ b/src/graph_list.c @@ -28,6 +28,11 @@ #include #include #include +#include +#include +#include + +#include #include "graph_list.h" #include "common.h" @@ -36,6 +41,7 @@ #include "graph_config.h" #include "graph_def.h" #include "graph_ident.h" +#include "graph_instance.h" #include "utils_cgi.h" #include "utils_search.h" @@ -46,6 +52,7 @@ * Defines */ #define UPDATE_INTERVAL 900 +#define CACHE_FILE "/tmp/collection4.json" /* * Global variables @@ -239,7 +246,7 @@ static int gl_dump (void) /* {{{ */ size_t i; /* FIXME: Lock the file */ - fh = fopen ("/tmp/collection4.json", "w"); + fh = fopen (CACHE_FILE, "w"); if (fh == NULL) return (errno); @@ -267,6 +274,307 @@ static int gl_dump (void) /* {{{ */ return (0); } /* }}} int gl_dump */ +/* + * JSON parsing functions + */ +#define CTX_MASK 0xff000000 +#define CTX_GRAPH 0x01000000 +#define CTX_GRAPH_SELECT 0x02000000 +#define CTX_INST 0x03000000 +#define CTX_INST_SELECT 0x04000000 +#define CTX_INST_FILE 0x05000000 + +#define CTX_IDENT_MASK 0x00ff0000 +#define CTX_IDENT_HOST 0x00010000 +#define CTX_IDENT_PLUGIN 0x00020000 +#define CTX_IDENT_PLUGIN_INSTANCE 0x00030000 +#define CTX_IDENT_TYPE 0x00040000 +#define CTX_IDENT_TYPE_INSTANCE 0x00050000 + +struct gl_json_context_s +{ + uint32_t state; + + graph_config_t *cfg; + graph_instance_t *inst; + graph_ident_t *ident; + + _Bool dynamic_graph; +}; +typedef struct gl_json_context_s gl_json_context_t; + +static void set_state (gl_json_context_t *ctx, /* {{{ */ + uint32_t new_state, uint32_t mask) +{ + uint32_t old_state = ctx->state; + ctx->state = (old_state & ~mask) | (new_state & mask); +} /* }}} void set_state */ + +static int gl_json_string (void *user_data, /* {{{ */ + const unsigned char *str, + unsigned int str_length) +{ + gl_json_context_t *ctx = user_data; + char buffer[str_length + 1]; + + memcpy (buffer, str, str_length); + buffer[str_length] = 0; + + if (((ctx->state & CTX_MASK) == CTX_GRAPH_SELECT) + || ((ctx->state & CTX_MASK) == CTX_INST_SELECT) + || ((ctx->state & CTX_MASK) == CTX_INST_FILE)) + { + switch (ctx->state & CTX_IDENT_MASK) + { + case CTX_IDENT_HOST: + ident_set_host (ctx->ident, buffer); + break; + case CTX_IDENT_PLUGIN: + ident_set_plugin (ctx->ident, buffer); + break; + case CTX_IDENT_PLUGIN_INSTANCE: + ident_set_plugin_instance (ctx->ident, buffer); + break; + case CTX_IDENT_TYPE: + ident_set_type (ctx->ident, buffer); + break; + case CTX_IDENT_TYPE_INSTANCE: + ident_set_type_instance (ctx->ident, buffer); + break; + } + } + + return (1); +} /* }}} int gl_json_string */ + +static int gl_json_end_map (void *user_data) /* {{{ */ +{ + gl_json_context_t *ctx = user_data; + + if ((ctx->state & CTX_MASK) == CTX_GRAPH_SELECT) + { + size_t i; + + /* ctx->ident should now hold the valid selector */ + assert (ctx->cfg == NULL); + assert (ctx->inst == NULL); + assert (ctx->ident != NULL); + + for (i = 0; i < gl_active_num; i++) + { + if (graph_compare (gl_active[i], ctx->ident) != 0) + continue; + + ctx->cfg = gl_active[i]; + ctx->dynamic_graph = 0; + break; + } + + if (ctx->cfg == NULL) + { + ctx->cfg = graph_create (ctx->ident); + ctx->dynamic_graph = 1; + } + + ident_destroy (ctx->ident); + ctx->ident = NULL; + + set_state (ctx, CTX_GRAPH, CTX_MASK); + } + else if ((ctx->state & CTX_MASK) == CTX_INST_SELECT) + { + /* ctx->ident should now hold the valid selector */ + assert (ctx->cfg != NULL); + assert (ctx->inst == NULL); + assert (ctx->ident != NULL); + + ctx->inst = inst_create (ctx->cfg, ctx->ident); + ident_destroy (ctx->ident); + ctx->ident = NULL; + + set_state (ctx, CTX_INST, CTX_MASK); + } + else if ((ctx->state & CTX_MASK) == CTX_INST_FILE) + { + /* ctx->ident should now hold the valid file */ + assert (ctx->cfg != NULL); + assert (ctx->inst != NULL); + assert (ctx->ident != NULL); + + inst_add_file (ctx->inst, ctx->ident); + ident_destroy (ctx->ident); + ctx->ident = NULL; + + /* Don't reset the state here, files are in an array. */ + } + else if ((ctx->state & CTX_MASK) == CTX_INST) + { + /* ctx->inst should now hold a complete instance */ + assert (ctx->cfg != NULL); + assert (ctx->inst != NULL); + assert (ctx->ident == NULL); + + graph_add_inst (ctx->cfg, ctx->inst); + /* don't destroy / free ctx->inst */ + ctx->inst = NULL; + + /* Don't reset the state here, instances are in an array. */ + } + else if ((ctx->state & CTX_MASK) == CTX_GRAPH) + { + /* ctx->cfg should now hold a complete graph */ + assert (ctx->cfg != NULL); + assert (ctx->inst == NULL); + assert (ctx->ident == NULL); + + if (ctx->dynamic_graph) + gl_add_graph_internal (ctx->cfg, &gl_dynamic, &gl_dynamic_num); + /* else: already contained in gl_active */ + ctx->cfg = NULL; + + /* Don't reset the state here, graphs are in an array. */ + } + + return (1); +} /* }}} int gl_json_end_map */ + +static int gl_json_end_array (void *user_data) /* {{{ */ +{ + gl_json_context_t *ctx = user_data; + + if ((ctx->state & CTX_MASK) == CTX_INST_FILE) + set_state (ctx, CTX_INST, CTX_MASK); + else if ((ctx->state & CTX_MASK) == CTX_INST) + set_state (ctx, CTX_GRAPH, CTX_MASK); + else if ((ctx->state & CTX_MASK) == CTX_GRAPH) + { + /* We're done */ + } + + return (1); +} /* }}} int gl_json_end_array */ + +static int gl_json_key (void *user_data, /* {{{ */ + const unsigned char *str, + unsigned int str_length) +{ + gl_json_context_t *ctx = user_data; + char buffer[str_length + 1]; + + memcpy (buffer, str, str_length); + buffer[str_length] = 0; + + if ((ctx->state & CTX_MASK) == CTX_GRAPH) + { + if (strcasecmp ("select", buffer) == 0) + set_state (ctx, CTX_GRAPH_SELECT, CTX_MASK); + else if (strcasecmp ("instances", buffer) == 0) + set_state (ctx, CTX_INST, CTX_MASK); + } + else if ((ctx->state & CTX_MASK) == CTX_INST) + { + if (strcasecmp ("select", buffer) == 0) + set_state (ctx, CTX_INST_SELECT, CTX_MASK); + else if (strcasecmp ("files", buffer) == 0) + set_state (ctx, CTX_INST_FILE, CTX_MASK); + } + else if (((ctx->state & CTX_MASK) == CTX_GRAPH_SELECT) + || ((ctx->state & CTX_MASK) == CTX_INST_SELECT) + || ((ctx->state & CTX_MASK) == CTX_INST_FILE)) + { + if (strcasecmp ("host", buffer) == 0) + set_state (ctx, CTX_IDENT_HOST, CTX_IDENT_MASK); + else if (strcasecmp ("plugin", buffer) == 0) + set_state (ctx, CTX_IDENT_PLUGIN, CTX_IDENT_MASK); + else if (strcasecmp ("plugin_instance", buffer) == 0) + set_state (ctx, CTX_IDENT_PLUGIN_INSTANCE, CTX_IDENT_MASK); + else if (strcasecmp ("type", buffer) == 0) + set_state (ctx, CTX_IDENT_TYPE, CTX_IDENT_MASK); + else if (strcasecmp ("type_instance", buffer) == 0) + set_state (ctx, CTX_IDENT_TYPE_INSTANCE, CTX_IDENT_MASK); + } + + return (0); +} /* }}} int gl_json_key */ + +yajl_callbacks gl_json_callbacks = +{ + /* null = */ NULL, + /* boolean = */ NULL, + /* integer = */ NULL, + /* double = */ NULL, + /* number = */ NULL, + /* string = */ gl_json_string, + /* start_map = */ NULL, + /* map_key = */ gl_json_key, + /* end_map = */ gl_json_end_map, + /* start_array = */ NULL, + /* end_array = */ gl_json_end_array +}; + +static int gl_read_cache (_Bool block) /* {{{ */ +{ + yajl_handle handle; + gl_json_context_t context; + yajl_parser_config handle_config = { /* comments = */ 0, /* check UTF-8 */ 0 }; + + int fd; + int cmd; + struct flock lock; + int status; + + fd = open (CACHE_FILE, O_RDONLY); + if (fd < 0) + { + fprintf (stderr, "gl_read_cache: open(2) failed with status %i\n", errno); + return (errno); + } + + if (block) + cmd = F_SETLKW; + else + cmd = F_SETLK; + + memset (&lock, 0, sizeof (lock)); + lock.l_type = F_RDLCK; + lock.l_whence = SEEK_SET; + lock.l_start = 0; + lock.l_len = 0; /* lock everything */ + + while (42) + { + status = fcntl (fd, cmd, &lock); + if (status == 0) + break; + + if (!block && ((errno == EACCES) || (errno == EAGAIN))) + { + close (fd); + return (0); + } + + if (errno == EINTR) + continue; + + fprintf (stderr, "gl_read_cache: fcntl(2) failed with status %i\n", + errno); + return (errno); + } + + memset (&context, 0, sizeof (context)); + context.cfg = NULL; + context.inst = NULL; + context.ident = NULL; + + handle = yajl_alloc (&gl_json_callbacks, + &handle_config, + /* alloc funcs = */ NULL, + &context); + + close (fd); + +} /* }}} int gl_read_cache */ + /* * Global functions */