| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package program |
| 4 | |
| 5 | import ( |
| 6 | "fmt" |
| 7 | "slices" |
| 8 | ) |
| 9 | |
| 10 | // Program is an immutable compiled chart-template snapshot consumed by chartengine. |
| 11 | // |
| 12 | // Immutability contract: |
| 13 | // - New(...) deep-copies all caller-provided slices/maps. |
| 14 | // - getters return copies, never internal backing storage. |
| 15 | // - all internal indexes are built once at construction time. |
| 16 | // |
| 17 | // This keeps runtime planning deterministic and race-free while templates are |
| 18 | // recompiled/reloaded in parallel runtime paths. |
| 19 | type Program struct { |
| 20 | version string |
| 21 | revision uint64 |
| 22 | |
| 23 | metrics map[string]struct{} |
| 24 | metricNames []string |
| 25 | charts []Chart |
| 26 | chartByTmpl map[string]int |
| 27 | chartOrderID []string |
| 28 | } |
| 29 | |
| 30 | // New constructs an immutable Program snapshot from precompiled IR items. |
| 31 | func New(version string, revision uint64, metrics []string, charts []Chart) (*Program, error) { |
| 32 | if version == "" { |
| 33 | return nil, fmt.Errorf("program: version is required") |
| 34 | } |
| 35 | |
| 36 | p := &Program{ |
| 37 | version: version, |
| 38 | revision: revision, |
| 39 | metrics: make(map[string]struct{}, len(metrics)), |
| 40 | charts: make([]Chart, 0, len(charts)), |
| 41 | chartByTmpl: make(map[string]int, len(charts)), |
| 42 | } |
| 43 | |
| 44 | for _, name := range metrics { |
| 45 | if name == "" { |
| 46 | return nil, fmt.Errorf("program: metric name cannot be empty") |
| 47 | } |
| 48 | if _, ok := p.metrics[name]; ok { |
| 49 | continue |
| 50 | } |
| 51 | p.metrics[name] = struct{}{} |
| 52 | p.metricNames = append(p.metricNames, name) |
| 53 | } |
| 54 | slices.Sort(p.metricNames) |
| 55 | |
| 56 | for i, chart := range charts { |
| 57 | if err := validateChart(chart); err != nil { |
| 58 | return nil, fmt.Errorf("program: chart[%d]: %w", i, err) |
| 59 | } |
| 60 | if _, exists := p.chartByTmpl[chart.TemplateID]; exists { |
| 61 | return nil, fmt.Errorf("program: duplicate chart template_id %q", chart.TemplateID) |
| 62 | } |
| 63 | |
| 64 | clone := chart.clone() |
| 65 | p.chartByTmpl[clone.TemplateID] = len(p.charts) |
| 66 | p.chartOrderID = append(p.chartOrderID, clone.TemplateID) |
| 67 | p.charts = append(p.charts, clone) |
| 68 | } |
| 69 | |
| 70 | return p, nil |
| 71 | } |
| 72 | |
| 73 | // Version returns the program schema/version marker. |
| 74 | func (p *Program) Version() string { return p.version } |
| 75 | |
| 76 | // Revision returns a deterministic revision/hash value assigned by compiler. |
| 77 | func (p *Program) Revision() uint64 { return p.revision } |
| 78 | |
| 79 | // MetricNames returns declared metric names in sorted deterministic order. |
| 80 | func (p *Program) MetricNames() []string { |
| 81 | return append([]string(nil), p.metricNames...) |
| 82 | } |
| 83 | |
| 84 | // HasMetric reports whether a metric name is declared in program scope. |
| 85 | func (p *Program) HasMetric(name string) bool { |
| 86 | _, ok := p.metrics[name] |
| 87 | return ok |
| 88 | } |
| 89 | |
| 90 | // ChartTemplateIDs returns chart template IDs in insertion order. |
| 91 | func (p *Program) ChartTemplateIDs() []string { |
| 92 | return append([]string(nil), p.chartOrderID...) |
| 93 | } |
| 94 | |
| 95 | // Charts returns a deep copy of compiled charts in insertion order. |
| 96 | func (p *Program) Charts() []Chart { |
| 97 | out := make([]Chart, 0, len(p.charts)) |
| 98 | for _, chart := range p.charts { |
| 99 | out = append(out, chart.clone()) |
| 100 | } |
| 101 | return out |
| 102 | } |
| 103 | |
| 104 | // Chart returns one chart by template ID. |
| 105 | func (p *Program) Chart(templateID string) (Chart, bool) { |
| 106 | idx, ok := p.chartByTmpl[templateID] |
| 107 | if !ok { |
| 108 | return Chart{}, false |
| 109 | } |
| 110 | return p.charts[idx].clone(), true |
| 111 | } |