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 size_t pc_queue_size(void);
  36
  37 /*
  38  * Write all the queued entries, returning 0 on success. If the number of
  39  * entries is smaller than the specified threshold, the operation is performed
  40  * sequentially.
  41  */
  42 int run_parallel_checkout(struct checkout *state, int num_workers, int threshold,
  43                           struct progress *progress, unsigned int *progress_cnt);
  44
  45 /****************************************************************
  46  * Interface with checkout--worker
  47  ****************************************************************/
  48
  49 enum pc_item_status {
  50         PC_ITEM_PENDING = 0,
  51         PC_ITEM_WRITTEN,
  52         /*
  53          * The entry could not be written because there was another file
  54          * already present in its path or leading directories. Since
  55          * checkout_entry_ca() removes such files from the working tree before
  56          * enqueueing the entry for parallel checkout, it means that there was
  57          * a path collision among the entries being written.
  58          */
  59         PC_ITEM_COLLIDED,
  60         PC_ITEM_FAILED,
  61 };
  62
  63 struct parallel_checkout_item {
  64         /*
  65          * In main process ce points to a istate->cache[] entry. Thus, it's not
  66          * owned by us. In workers they own the memory, which *must be* released.
  67          */
  68         struct cache_entry *ce;
  69         struct conv_attrs ca;
  70         size_t id; /* position in parallel_checkout.items[] of main process */
  71
  72         /* Output fields, sent from workers. */
  73         enum pc_item_status status;
  74         struct stat st;
  75 };
  76
  77 /*
  78  * The fixed-size portion of `struct parallel_checkout_item` that is sent to the
  79  * workers. Following this will be 2 strings: ca.working_tree_encoding and
  80  * ce.name; These are NOT null terminated, since we have the size in the fixed
  81  * portion.
  82  *
  83  * Note that not all fields of conv_attrs and cache_entry are passed, only the
  84  * ones that will be required by the workers to smudge and write the entry.
  85  */
  86 struct pc_item_fixed_portion {
  87         size_t id;
  88         struct object_id oid;
  89         unsigned int ce_mode;
  90         enum convert_crlf_action crlf_action;
  91         int ident;
  92         size_t working_tree_encoding_len;
  93         size_t name_len;
  94 };
  95
  96 /*
  97  * The fields of `struct parallel_checkout_item` that are returned by the
  98  * workers. Note: `st` must be the last one, as it is omitted on error.
  99  */
 100 struct pc_item_result {
 101         size_t id;
 102         enum pc_item_status status;
 103         struct stat st;
 104 };
 105
 106 #define PC_ITEM_RESULT_BASE_SIZE offsetof(struct pc_item_result, st)
 107
 108 void write_pc_item(struct parallel_checkout_item *pc_item,
 109                    struct checkout *state);
 110
 111 #endif /* PARALLEL_CHECKOUT_H */