parallel-checkout.h

   1 #ifndef PARALLEL_CHECKOUT_H
   2 #define PARALLEL_CHECKOUT_H
   3
   4 #include "convert.h"
   5
   6 struct cache_entry;
   7 struct checkout;
   8 struct progress;
   9
  10 /****************************************************************
  11  * Users of parallel checkout
  12  ****************************************************************/
  13
  14 enum pc_status {
  15         PC_UNINITIALIZED = 0,
  16         PC_ACCEPTING_ENTRIES,
  17         PC_RUNNING,
  18 };
  19
  20 enum pc_status parallel_checkout_status(void);
  21 void get_parallel_checkout_configs(int *num_workers, int *threshold);
  22
  23 /*
  24  * Put parallel checkout into the PC_ACCEPTING_ENTRIES state. Should be used
  25  * only when in the PC_UNINITIALIZED state.
  26  */
  27 void init_parallel_checkout(void);
  28
  29 /*
  30  * Return -1 if parallel checkout is currently not accepting entries or if the
  31  * entry is not eligible for parallel checkout. Otherwise, enqueue the entry
  32  * for later write and return 0.
  33  */
  34 int enqueue_checkout(struct cache_entry *ce, struct conv_attrs *ca,
  35                      int *checkout_counter);
  36 size_t pc_queue_size(void);
  37
  38 /*
  39  * Write all the queued entries, returning 0 on success. If the number of
  40  * entries is smaller than the specified threshold, the operation is performed
  41  * sequentially.
  42  */
  43 int run_parallel_checkout(struct checkout *state, int num_workers, int threshold,
  44                           struct progress *progress, unsigned int *progress_cnt);
  45
  46 /****************************************************************
  47  * Interface with checkout--worker
  48  ****************************************************************/
  49
  50 enum pc_item_status {
  51         PC_ITEM_PENDING = 0,
  52         PC_ITEM_WRITTEN,
  53         /*
  54          * The entry could not be written because there was another file
  55          * already present in its path or leading directories. Since
  56          * checkout_entry_ca() removes such files from the working tree before
  57          * enqueueing the entry for parallel checkout, it means that there was
  58          * a path collision among the entries being written.
  59          */
  60         PC_ITEM_COLLIDED,
  61         PC_ITEM_FAILED,
  62 };
  63
  64 struct parallel_checkout_item {
  65         /*
  66          * In main process ce points to a istate->cache[] entry. Thus, it's not
  67          * owned by us. In workers they own the memory, which *must be* released.
  68          */
  69         struct cache_entry *ce;
  70         struct conv_attrs ca;
  71         size_t id; /* position in parallel_checkout.items[] of main process */
  72         int *checkout_counter;
  73
  74         /* Output fields, sent from workers. */
  75         enum pc_item_status status;
  76         struct stat st;
  77 };
  78
  79 /*
  80  * The fixed-size portion of `struct parallel_checkout_item` that is sent to the
  81  * workers. Following this will be 2 strings: ca.working_tree_encoding and
  82  * ce.name; These are NOT null terminated, since we have the size in the fixed
  83  * portion.
  84  *
  85  * Note that not all fields of conv_attrs and cache_entry are passed, only the
  86  * ones that will be required by the workers to smudge and write the entry.
  87  */
  88 struct pc_item_fixed_portion {
  89         size_t id;
  90         struct object_id oid;
  91         unsigned int ce_mode;
  92         enum convert_crlf_action crlf_action;
  93         int ident;
  94         size_t working_tree_encoding_len;
  95         size_t name_len;
  96 };
  97
  98 /*
  99  * The fields of `struct parallel_checkout_item` that are returned by the
 100  * workers. Note: `st` must be the last one, as it is omitted on error.
 101  */
 102 struct pc_item_result {
 103         size_t id;
 104         enum pc_item_status status;
 105         struct stat st;
 106 };
 107
 108 #define PC_ITEM_RESULT_BASE_SIZE offsetof(struct pc_item_result, st)
 109
 110 void write_pc_item(struct parallel_checkout_item *pc_item,
 111                    struct checkout *state);
 112
 113 #endif /* PARALLEL_CHECKOUT_H */