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MySQL 9.2.0
Source Code Documentation
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Hash storage. More...
Go to the source code of this file.
Functions | |
static ha_storage_t * | ha_storage_create (ulint initial_heap_bytes, ulint initial_hash_cells) |
Creates a hash storage. More... | |
const void * | ha_storage_put_memlim (ha_storage_t *storage, const void *data, ulint data_len, ulint memlim) |
Copies data into the storage and returns a pointer to the copy. More... | |
static const void * | ha_storage_put (ha_storage_t *storage, const void *data, ulint data_len) |
Same as ha_storage_put_memlim() but without memory limit. More... | |
static const char * | ha_storage_put_str (ha_storage_t *storage, const char *str) |
Copies string into the storage and returns a pointer to the copy. More... | |
static const char * | ha_storage_put_str_memlim (ha_storage_t *storage, const char *str, ulint memlim) |
Copies string into the storage and returns a pointer to the copy obeying a memory limit. More... | |
static void | ha_storage_empty (ha_storage_t **storage) |
Empties a hash storage, freeing memory occupied by data chunks. More... | |
static void | ha_storage_free (ha_storage_t *storage) |
Frees a hash storage and everything it contains, it cannot be used after this call. More... | |
static ulint | ha_storage_get_size (const ha_storage_t *storage) |
Gets the size of the memory used by a storage. More... | |
Variables | |
constexpr uint32_t | HA_STORAGE_DEFAULT_HEAP_BYTES = 1024 |
This value is used by default by ha_storage_create(). More... | |
constexpr uint32_t | HA_STORAGE_DEFAULT_HASH_CELLS = 4096 |
This value is used by default by ha_storage_create(). More... | |
Hash storage.
Provides a data structure that stores chunks of data in its own storage, avoiding duplicates.
Created September 22, 2007 Vasil Dimov
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inlinestatic |
Creates a hash storage.
If any of the parameters is 0, then a default value is used.
[in] | initial_hash_cells | initial number of cells in the hash table |
[in] | initial_heap_bytes | initial heap's size |
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inlinestatic |
Empties a hash storage, freeing memory occupied by data chunks.
This invalidates any pointers previously returned by ha_storage_put(). The hash storage is not invalidated itself and can be used again. in/out: hash storage
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inlinestatic |
Frees a hash storage and everything it contains, it cannot be used after this call.
This invalidates any pointers previously returned by ha_storage_put(). in, own: hash storage
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inlinestatic |
Gets the size of the memory used by a storage.
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inlinestatic |
Same as ha_storage_put_memlim() but without memory limit.
storage | in/out: hash storage |
data | in: data to store |
data_len | in: data length |
const void * ha_storage_put_memlim | ( | ha_storage_t * | storage, |
const void * | data, | ||
ulint | data_len, | ||
ulint | memlim | ||
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Copies data into the storage and returns a pointer to the copy.
If the same data chunk is already present, then pointer to it is returned. Data chunks are considered to be equal if len1 == len2 and memcmp(data1, data2, len1) == 0. If "data" is not present (and thus data_len bytes need to be allocated) and the size of storage is going to become more than "memlim" then "data" is not added and NULL is returned. To disable this behavior "memlim" can be set to 0, which stands for "no limit".
If the same data chunk is already present, then pointer to it is returned. Data chunks are considered to be equal if len1 == len2 and memcmp(data1, data2, len1) == 0. If "data" is not present (and thus data_len bytes need to be allocated) and the size of storage is going to become more than "memlim" then "data" is not added and NULL is returned. To disable this behavior "memlim" can be set to 0, which stands for "no limit".
storage | in/out: hash storage |
data | in: data to store |
data_len | in: data length |
memlim | in: memory limit to obey |
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inlinestatic |
Copies string into the storage and returns a pointer to the copy.
If the same string is already present, then pointer to it is returned. Strings are considered to be equal if strcmp(str1, str2) == 0.
storage | in/out: hash storage |
str | in: string to put |
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inlinestatic |
Copies string into the storage and returns a pointer to the copy obeying a memory limit.
If the same string is already present, then pointer to it is returned. Strings are considered to be equal if strcmp(str1, str2) == 0.
storage | in/out: hash storage |
str | in: string to put |
memlim | in: memory limit to obey |
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constexpr |
This value is used by default by ha_storage_create().
It is a constant per ha_storage's lifetime.
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constexpr |
This value is used by default by ha_storage_create().
More memory is allocated later when/if it is needed.