APC函数集：存储与管理PHP缓存的关键操作

apc_add — 缓存一个变量到数据存储
apc_bin_dump — Get a binary dump of the given files and user variables
apc_bin_dumpfile — Output a binary dump of cached files and user variables to a file
apc_bin_load — Load a binary dump into the APC file/user cache
apc_bin_loadfile — Load a binary dump from a file into the APC file/user cache
apc_cache_info — Retrieves cached information from APC's data store
apc_cas — Updates an old value with a new value
apc_clear_cache — 清除APC缓存
apc_compile_file — Stores a file in the bytecode cache, bypassing all filters.
apc_dec — Decrease a stored number
apc_define_constants — Defines a set of constants for retrieval and mass-definition
apc_delete_file — Deletes files from the opcode cache
apc_delete — Removes a stored variable from the cache
apc_exists — 检查APC中是否存在某个或者某些key
apc_fetch — 从缓存中取出存储的变量
apc_inc — Increase a stored number
apc_load_constants — Loads a set of constants from the cache
apc_sma_info — Retrieves APC's Shared Memory Allocation information
apc_store — Cache a variable in the data store
debug_backtrace — Generates a backtrace
debug_print_backtrace — Prints a backtrace
error_get_last — Get the last occurred error
error_log — Send an error message somewhere
error_reporting — Sets which PHP errors are reported
restore_error_handler — Restores the previous error handler function
restore_exception_handler — Restores the previously defined exception handler function
set_error_handler — Sets a user-defined error handler function
set_exception_handler — Sets a user-defined exception handler function
trigger_error — Generates a user-level error/warning/notice message
user_error — Alias of trigger_error