mdl_cache.h

Go to the documentation of this file.

#pragma once
 
#include <stddef.h>
#include <stdint.h>
 
#include "mdl_config.h"
#include "mdl_net.h"
#include "mdl_state.h"
#include "mdl_storage.h"
#include "ra8_err.h"
#include "ra8_io_stream.h"

typedef enum : uint16_t {
  k_mdl_cache_schema_version = 1U,   
  k_mdl_cache_record_max     = 128U, 
} mdl_cache_limit_t;

typedef struct {
  char     url[k_mdl_url_max];                
  char     relative_path[k_mdl_relpath_max];  
  char     etag[k_mdl_etag_max];              
  char     last_modified[k_mdl_last_mod_max]; 
  uint64_t url_hash;                          
  uint64_t content_hash;                      
  int64_t  fetched_at;                        
  uint16_t response_status;                   
} mdl_cache_record_t;

typedef struct {
  mdl_cache_record_t records[k_mdl_cache_record_max]; 
  uint64_t           host_hash;                       
  uint16_t           schema_version;                  
  uint16_t           record_count;                    
} mdl_cache_index_t;

typedef ra8_err_t (*mdl_cache_fetch_fn)(void*                context,
                                        const char*          url,
                                        const mdl_net_req_t* request,
                                        char*                buffer,
                                        size_t               capacity,
                                        size_t*              out_length,
                                        mdl_net_resp_t*      response);

typedef struct {
  mdl_storage_t*     storage;    
  mdl_cache_index_t* index;      
  const char*        root;       
  ra8_io_stream_t*   diagnostic; 
  bool               refetch;    
} mdl_cache_t;

typedef struct {
  int64_t  age_seconds;     
  uint16_t observed_status; 
  bool     body_reused;     
  bool     revalidated;     
  bool     index_rebuilt;   
} mdl_cache_result_t;

[[nodiscard]] ra8_err_t mdl_cache_get_buf(mdl_cache_t*         cache,
                                          const char*          url,
                                          const mdl_net_req_t* base_request,
                                          mdl_cache_fetch_fn   fetch,
                                          void*                fetch_context,
                                          char*                buffer,
                                          size_t               capacity,
                                          size_t*              out_length,
                                          mdl_net_resp_t*      response,
                                          mdl_cache_result_t*  result);