1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
#include <Processors/Merges/IMergingTransform.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
extern const int NOT_IMPLEMENTED;
}
IMergingTransformBase::IMergingTransformBase(
size_t num_inputs,
const Block & input_header,
const Block & output_header,
bool have_all_inputs_,
UInt64 limit_hint_,
bool always_read_till_end_)
: IProcessor(InputPorts(num_inputs, input_header), {output_header})
, have_all_inputs(have_all_inputs_)
, limit_hint(limit_hint_)
, always_read_till_end(always_read_till_end_)
{
}
static InputPorts createPorts(const Blocks & blocks)
{
InputPorts ports;
for (const auto & block : blocks)
ports.emplace_back(block);
return ports;
}
IMergingTransformBase::IMergingTransformBase(
const Blocks & input_headers,
const Block & output_header,
bool have_all_inputs_,
UInt64 limit_hint_,
bool always_read_till_end_)
: IProcessor(createPorts(input_headers), {output_header})
, have_all_inputs(have_all_inputs_)
, limit_hint(limit_hint_)
, always_read_till_end(always_read_till_end_)
{
}
void IMergingTransformBase::onNewInput()
{
throw Exception(ErrorCodes::NOT_IMPLEMENTED, "onNewInput is not implemented for {}", getName());
}
void IMergingTransformBase::addInput()
{
if (have_all_inputs)
throw Exception(ErrorCodes::LOGICAL_ERROR, "IMergingTransform already have all inputs.");
inputs.emplace_back(outputs.front().getHeader(), this);
onNewInput();
}
void IMergingTransformBase::setHaveAllInputs()
{
if (have_all_inputs)
throw Exception(ErrorCodes::LOGICAL_ERROR, "IMergingTransform already have all inputs.");
have_all_inputs = true;
}
IProcessor::Status IMergingTransformBase::prepareInitializeInputs()
{
/// Add information about inputs.
if (input_states.empty())
{
input_states.reserve(inputs.size());
for (auto & input : inputs)
input_states.emplace_back(input);
state.init_chunks.resize(inputs.size());
}
/// Check for inputs we need.
bool all_inputs_has_data = true;
auto it = inputs.begin();
for (size_t i = 0; it != inputs.end(); ++i, ++it)
{
auto & input = *it;
if (input.isFinished())
continue;
if (input_states[i].is_initialized)
continue;
input.setNeeded();
if (!input.hasData())
{
all_inputs_has_data = false;
continue;
}
/// setNotNeeded after reading first chunk, because in optimismtic case
/// (e.g. with optimized 'ORDER BY primary_key LIMIT n' and small 'n')
/// we won't have to read any chunks anymore;
auto chunk = input.pull(limit_hint != 0);
if ((limit_hint && chunk.getNumRows() < limit_hint) || always_read_till_end)
input.setNeeded();
if (!chunk.hasRows())
{
if (!input.isFinished())
{
input.setNeeded();
all_inputs_has_data = false;
}
continue;
}
state.init_chunks[i].set(std::move(chunk));
input_states[i].is_initialized = true;
}
if (!all_inputs_has_data)
return Status::NeedData;
is_initialized = true;
return Status::Ready;
}
IProcessor::Status IMergingTransformBase::prepare()
{
if (!have_all_inputs)
return Status::NeedData;
auto & output = outputs.front();
/// Special case for no inputs.
if (inputs.empty())
{
output.finish();
onFinish();
return Status::Finished;
}
/// Check can output.
if (output.isFinished())
{
for (auto & in : inputs)
in.close();
onFinish();
return Status::Finished;
}
/// Do not disable inputs, so they can be executed in parallel.
bool is_port_full = !output.canPush();
/// Push if has data.
if ((state.output_chunk || state.output_chunk.hasChunkInfo()) && !is_port_full)
output.push(std::move(state.output_chunk));
if (!is_initialized)
return prepareInitializeInputs();
if (state.is_finished)
{
if (is_port_full)
return Status::PortFull;
if (always_read_till_end)
{
for (auto & input : inputs)
{
if (!input.isFinished())
{
input.setNeeded();
if (input.hasData())
std::ignore = input.pull();
return Status::NeedData;
}
}
}
for (auto & input : inputs)
input.close();
outputs.front().finish();
onFinish();
return Status::Finished;
}
if (state.need_data)
{
auto & input = input_states[state.next_input_to_read].port;
if (!input.isFinished())
{
input.setNeeded();
if (!input.hasData())
return Status::NeedData;
state.input_chunk.set(input.pull());
if (!state.input_chunk.chunk.hasRows() && !input.isFinished())
return Status::NeedData;
state.has_input = true;
}
else
{
state.no_data = true;
}
state.need_data = false;
}
if (is_port_full)
return Status::PortFull;
return Status::Ready;
}
}
|
